diff --git a/flang/lib/Semantics/check-acc-structure.cpp b/flang/lib/Semantics/check-acc-structure.cpp
index 4a5798a8a531a..d69e1c597e2fb 100644
--- a/flang/lib/Semantics/check-acc-structure.cpp
+++ b/flang/lib/Semantics/check-acc-structure.cpp
@@ -69,7 +69,12 @@ static constexpr inline AccClauseSet updateOnlyAllowedAfterDeviceTypeClauses{
 
 static constexpr inline AccClauseSet routineOnlyAllowedAfterDeviceTypeClauses{
     llvm::acc::Clause::ACCC_bind, llvm::acc::Clause::ACCC_gang,
-    llvm::acc::Clause::ACCC_vector, llvm::acc::Clause::ACCC_worker};
+    llvm::acc::Clause::ACCC_vector, llvm::acc::Clause::ACCC_worker,
+    llvm::acc::Clause::ACCC_seq};
+
+static constexpr inline AccClauseSet routineMutuallyExclusiveClauses{
+    llvm::acc::Clause::ACCC_gang, llvm::acc::Clause::ACCC_worker,
+    llvm::acc::Clause::ACCC_vector, llvm::acc::Clause::ACCC_seq};
 
 bool AccStructureChecker::CheckAllowedModifier(llvm::acc::Clause clause) {
   if (GetContext().directive == llvm::acc::ACCD_enter_data ||
@@ -388,7 +393,6 @@ CHECK_SIMPLE_CLAUSE(NoCreate, ACCC_no_create)
 CHECK_SIMPLE_CLAUSE(Nohost, ACCC_nohost)
 CHECK_SIMPLE_CLAUSE(Private, ACCC_private)
 CHECK_SIMPLE_CLAUSE(Read, ACCC_read)
-CHECK_SIMPLE_CLAUSE(Seq, ACCC_seq)
 CHECK_SIMPLE_CLAUSE(UseDevice, ACCC_use_device)
 CHECK_SIMPLE_CLAUSE(Wait, ACCC_wait)
 CHECK_SIMPLE_CLAUSE(Write, ACCC_write)
@@ -532,18 +536,40 @@ void AccStructureChecker::Enter(const parser::AccClause::DeviceType &d) {
                 .str()),
         ContextDirectiveAsFortran());
   }
+  ResetCrtGroup();
+}
+
+void AccStructureChecker::Enter(const parser::AccClause::Seq &g) {
+  llvm::acc::Clause crtClause = llvm::acc::Clause::ACCC_seq;
+  if (GetContext().directive == llvm::acc::Directive::ACCD_routine) {
+    CheckMutuallyExclusivePerGroup(crtClause,
+        llvm::acc::Clause::ACCC_device_type, routineMutuallyExclusiveClauses);
+  }
+  CheckAllowed(crtClause);
 }
 
 void AccStructureChecker::Enter(const parser::AccClause::Vector &g) {
-  CheckAllowed(llvm::acc::Clause::ACCC_vector);
-  CheckAllowedOncePerGroup(
-      llvm::acc::Clause::ACCC_vector, llvm::acc::Clause::ACCC_device_type);
+  llvm::acc::Clause crtClause = llvm::acc::Clause::ACCC_vector;
+  if (GetContext().directive == llvm::acc::Directive::ACCD_routine) {
+    CheckMutuallyExclusivePerGroup(crtClause,
+        llvm::acc::Clause::ACCC_device_type, routineMutuallyExclusiveClauses);
+  }
+  CheckAllowed(crtClause);
+  if (GetContext().directive != llvm::acc::Directive::ACCD_routine) {
+    CheckAllowedOncePerGroup(crtClause, llvm::acc::Clause::ACCC_device_type);
+  }
 }
 
 void AccStructureChecker::Enter(const parser::AccClause::Worker &g) {
-  CheckAllowed(llvm::acc::Clause::ACCC_worker);
-  CheckAllowedOncePerGroup(
-      llvm::acc::Clause::ACCC_worker, llvm::acc::Clause::ACCC_device_type);
+  llvm::acc::Clause crtClause = llvm::acc::Clause::ACCC_worker;
+  if (GetContext().directive == llvm::acc::Directive::ACCD_routine) {
+    CheckMutuallyExclusivePerGroup(crtClause,
+        llvm::acc::Clause::ACCC_device_type, routineMutuallyExclusiveClauses);
+  }
+  CheckAllowed(crtClause);
+  if (GetContext().directive != llvm::acc::Directive::ACCD_routine) {
+    CheckAllowedOncePerGroup(crtClause, llvm::acc::Clause::ACCC_device_type);
+  }
 }
 
 void AccStructureChecker::Enter(const parser::AccClause::Tile &g) {
@@ -553,24 +579,32 @@ void AccStructureChecker::Enter(const parser::AccClause::Tile &g) {
 }
 
 void AccStructureChecker::Enter(const parser::AccClause::Gang &g) {
-  CheckAllowed(llvm::acc::Clause::ACCC_gang);
-  CheckAllowedOncePerGroup(
-      llvm::acc::Clause::ACCC_gang, llvm::acc::Clause::ACCC_device_type);
+  llvm::acc::Clause crtClause = llvm::acc::Clause::ACCC_gang;
+  if (GetContext().directive == llvm::acc::Directive::ACCD_routine) {
+    CheckMutuallyExclusivePerGroup(crtClause,
+        llvm::acc::Clause::ACCC_device_type, routineMutuallyExclusiveClauses);
+  }
+  CheckAllowed(crtClause);
+  if (GetContext().directive != llvm::acc::Directive::ACCD_routine) {
+    CheckAllowedOncePerGroup(crtClause, llvm::acc::Clause::ACCC_device_type);
+  }
 
   if (g.v) {
     bool hasNum = false;
     bool hasDim = false;
     const Fortran::parser::AccGangArgList &x = *g.v;
     for (const Fortran::parser::AccGangArg &gangArg : x.v) {
-      if (std::get_if<Fortran::parser::AccGangArg::Num>(&gangArg.u))
+      if (std::get_if<Fortran::parser::AccGangArg::Num>(&gangArg.u)) {
         hasNum = true;
-      else if (std::get_if<Fortran::parser::AccGangArg::Dim>(&gangArg.u))
+      } else if (std::get_if<Fortran::parser::AccGangArg::Dim>(&gangArg.u)) {
         hasDim = true;
+      }
     }
 
-    if (hasDim && hasNum)
+    if (hasDim && hasNum) {
       context_.Say(GetContext().clauseSource,
           "The num argument is not allowed when dim is specified"_err_en_US);
+    }
   }
 }
 
diff --git a/flang/lib/Semantics/check-directive-structure.h b/flang/lib/Semantics/check-directive-structure.h
index f7a6233a32edd..829405f99d64c 100644
--- a/flang/lib/Semantics/check-directive-structure.h
+++ b/flang/lib/Semantics/check-directive-structure.h
@@ -197,6 +197,7 @@ class DirectiveStructureChecker : public virtual BaseChecker {
     const PC *clause{nullptr};
     ClauseMapTy clauseInfo;
     std::list<C> actualClauses;
+    std::list<C> crtGroup;
     Symbol *loopIV{nullptr};
   };
 
@@ -261,6 +262,12 @@ class DirectiveStructureChecker : public virtual BaseChecker {
     GetContext().actualClauses.push_back(type);
   }
 
+  void AddClauseToCrtGroupInContext(C type) {
+    GetContext().crtGroup.push_back(type);
+  }
+
+  void ResetCrtGroup() { GetContext().crtGroup.clear(); }
+
   // Check if the given clause is present in the current context
   const PC *FindClause(C type) { return FindClause(GetContext(), type); }
 
@@ -353,6 +360,9 @@ class DirectiveStructureChecker : public virtual BaseChecker {
   // separator clause appears.
   void CheckAllowedOncePerGroup(C clause, C separator);
 
+  void CheckMutuallyExclusivePerGroup(
+      C clause, C separator, common::EnumSet<C, ClauseEnumSize> set);
+
   void CheckAtLeastOneClause();
 
   void CheckNotAllowedIfClause(
@@ -526,6 +536,7 @@ void DirectiveStructureChecker<D, C, PC, ClauseEnumSize>::CheckAllowed(
   }
   SetContextClauseInfo(clause);
   AddClauseToCrtContext(clause);
+  AddClauseToCrtGroupInContext(clause);
 }
 
 // Enforce restriction where clauses in the given set are not allowed if the
@@ -570,6 +581,37 @@ void DirectiveStructureChecker<D, C, PC,
   }
 }
 
+template <typename D, typename C, typename PC, std::size_t ClauseEnumSize>
+void DirectiveStructureChecker<D, C, PC,
+    ClauseEnumSize>::CheckMutuallyExclusivePerGroup(C clause, C separator,
+    common::EnumSet<C, ClauseEnumSize> set) {
+
+  // Checking of there is any offending clauses before the first separator.
+  for (auto cl : GetContext().actualClauses) {
+    if (cl == separator) {
+      break;
+    }
+    if (set.test(cl)) {
+      context_.Say(GetContext().directiveSource,
+          "Clause %s is not allowed if clause %s appears on the %s directive"_err_en_US,
+          parser::ToUpperCaseLetters(getClauseName(clause).str()),
+          parser::ToUpperCaseLetters(getClauseName(cl).str()),
+          ContextDirectiveAsFortran());
+    }
+  }
+
+  // Checking for mutually exclusive clauses in the current group.
+  for (auto cl : GetContext().crtGroup) {
+    if (set.test(cl)) {
+      context_.Say(GetContext().directiveSource,
+          "Clause %s is not allowed if clause %s appears on the %s directive"_err_en_US,
+          parser::ToUpperCaseLetters(getClauseName(clause).str()),
+          parser::ToUpperCaseLetters(getClauseName(cl).str()),
+          ContextDirectiveAsFortran());
+    }
+  }
+}
+
 // Check the value of the clause is a constant positive integer.
 template <typename D, typename C, typename PC, std::size_t ClauseEnumSize>
 void DirectiveStructureChecker<D, C, PC,
diff --git a/flang/test/Semantics/OpenACC/acc-routine.f90 b/flang/test/Semantics/OpenACC/acc-routine.f90
index 4dcb849c642c8..42762f537b8bc 100644
--- a/flang/test/Semantics/OpenACC/acc-routine.f90
+++ b/flang/test/Semantics/OpenACC/acc-routine.f90
@@ -13,3 +13,114 @@ subroutine sub2(a)
 subroutine sub3()
   !$acc routine bind(sub1)
 end subroutine
+
+subroutine sub6()
+  !ERROR: Clause GANG is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang gang
+
+  !ERROR: Clause GANG is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker gang
+
+  !ERROR: Clause GANG is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector gang
+
+  !ERROR: Clause GANG is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq gang
+
+  !ERROR: Clause WORKER is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker worker
+
+  !ERROR: Clause WORKER is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang worker
+
+  !ERROR: Clause WORKER is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector worker
+
+  !ERROR: Clause WORKER is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq worker
+
+  !ERROR: Clause VECTOR is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector vector
+
+  !ERROR: Clause VECTOR is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang vector
+
+  !ERROR: Clause VECTOR is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker vector
+
+  !ERROR: Clause VECTOR is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq vector
+
+  !ERROR: Clause SEQ is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq seq
+
+  !ERROR: Clause SEQ is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang seq
+
+  !ERROR: Clause SEQ is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker seq
+
+  !ERROR: Clause SEQ is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector seq
+
+end subroutine
+
+subroutine sub7()
+  !$acc routine device_type(*) gang device_type(host) worker
+
+  !ERROR: Clause SEQ is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine device_type(*) gang seq
+
+  !ERROR: Clause WORKER is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine device_type(*) gang worker
+
+  !ERROR: Clause GANG is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang device_type(*) gang
+
+  !ERROR: Clause WORKER is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang device_type(*) worker
+
+  !ERROR: Clause VECTOR is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang device_type(*) vector
+
+  !ERROR: Clause SEQ is not allowed if clause GANG appears on the ROUTINE directive
+  !$acc routine gang device_type(*) seq
+
+  !ERROR: Clause WORKER is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker device_type(*) worker
+
+  !ERROR: Clause GANG is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker device_type(*) gang
+
+  !ERROR: Clause VECTOR is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker device_type(*) vector
+
+  !ERROR: Clause SEQ is not allowed if clause WORKER appears on the ROUTINE directive
+  !$acc routine worker device_type(*) seq
+
+  !ERROR: Clause VECTOR is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector device_type(*) vector
+
+  !ERROR: Clause GANG is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector device_type(*) gang
+
+  !ERROR: Clause VECTOR is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector device_type(*) vector
+
+  !ERROR: Clause SEQ is not allowed if clause VECTOR appears on the ROUTINE directive
+  !$acc routine vector device_type(*) seq
+
+  !ERROR: Clause SEQ is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq device_type(*) seq
+
+  !ERROR: Clause GANG is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq device_type(*) gang
+
+  !ERROR: Clause VECTOR is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq device_type(*) vector
+
+  !ERROR: Clause WORKER is not allowed if clause SEQ appears on the ROUTINE directive
+  !$acc routine seq device_type(*) worker
+
+  !$acc routine device_type(host) seq device_type(nvidia) gang device_type(multicore) vector device_type(*) worker
+end subroutine