diff --git a/src/main/java/org/xmlet/xsdparser/xsdelements/XsdRestriction.java b/src/main/java/org/xmlet/xsdparser/xsdelements/XsdRestriction.java
index 9c17011..5fefed9 100644
--- a/src/main/java/org/xmlet/xsdparser/xsdelements/XsdRestriction.java
+++ b/src/main/java/org/xmlet/xsdparser/xsdelements/XsdRestriction.java
@@ -85,9 +85,9 @@ public class XsdRestriction extends XsdAnnotatedElements {
     private XsdMinLength minLength;
 
     /**
-     * A {@link XsdPattern} instance that specifies a regex pattern that a String type should follow.
+     * A List of{@link XsdPattern} items, that represent a set of pattern that a String type should follow.
      */
-    private XsdPattern pattern;
+    private List<XsdPattern> pattern = new ArrayList<>();
 
     /**
      * A {@link XsdTotalDigits} instance that specifies the total number of digits that a numeric type is allowed to have.
@@ -217,7 +217,7 @@ public XsdRestriction clone(@NotNull Map<String, String> placeHolderAttributes)
         }
 
         if (this.pattern != null){
-            elementCopy.pattern = (XsdPattern) this.pattern.clone(pattern.getAttributesMap(), elementCopy);
+            elementCopy.pattern = this.pattern.stream().map(patternObj -> (XsdPattern) patternObj.clone(patternObj.getAttributesMap(), elementCopy)).collect(Collectors.toList());
         }
 
         if (this.totalDigits != null){
@@ -389,14 +389,18 @@ public void setMinLength(XsdMinLength minLength) {
         this.minLength = minLength;
     }
 
-    public XsdPattern getPattern() {
+    public List<XsdPattern> getPattern() {
         return pattern;
     }
 
-    public void setPattern(XsdPattern pattern) {
+    public void setPattern(List<XsdPattern> pattern) {
         this.pattern = pattern;
     }
 
+    public void add(XsdPattern patternMember) {
+        pattern.add(patternMember);
+    }
+
     public XsdTotalDigits getTotalDigits() {
         return totalDigits;
     }
diff --git a/src/main/java/org/xmlet/xsdparser/xsdelements/XsdSimpleType.java b/src/main/java/org/xmlet/xsdparser/xsdelements/XsdSimpleType.java
index cf1d8c3..cbc0fa2 100644
--- a/src/main/java/org/xmlet/xsdparser/xsdelements/XsdSimpleType.java
+++ b/src/main/java/org/xmlet/xsdparser/xsdelements/XsdSimpleType.java
@@ -195,7 +195,6 @@ public List<XsdRestriction> getAllRestrictions() {
      * @param newRestriction The new restriction.
      */
     private void updateExistingRestriction(XsdRestriction existing, XsdRestriction newRestriction) {
-        XsdPattern pattern = newRestriction.getPattern();
         XsdMaxExclusive maxExclusive = newRestriction.getMaxExclusive();
         XsdMaxInclusive maxInclusive = newRestriction.getMaxInclusive();
         XsdMaxLength maxLength = newRestriction.getMaxLength();
@@ -207,9 +206,6 @@ private void updateExistingRestriction(XsdRestriction existing, XsdRestriction n
         XsdTotalDigits totalDigits = newRestriction.getTotalDigits();
         XsdWhiteSpace whiteSpace = newRestriction.getWhiteSpace();
 
-        if (pattern != null){
-            existing.setPattern(pattern);
-        }
 
         if (maxExclusive != null){
             existing.setMaxExclusive(maxExclusive);
@@ -252,6 +248,29 @@ private void updateExistingRestriction(XsdRestriction existing, XsdRestriction n
         }
 
         updateExistingRestrictionEnumerations(existing, newRestriction);
+        updateExistingRestricionPatterns(existing, newRestriction);
+    }
+
+    /**
+     * Updates the existing {@link XsdRestriction} with the restrictions of the new {@link XsdRestriction} instance.
+     * @param existing The existing {@link XsdRestriction} instance.
+     * @param newRestriction The new {@link XsdRestriction} instance.
+     */
+    private void updateExistingRestricionPatterns(XsdRestriction existing, XsdRestriction newRestriction) {
+        List<XsdPattern> existingPattern = existing.getPattern();
+        List<XsdPattern> newRestrictionPattern = newRestriction.getPattern();
+
+        if (existingPattern == null){
+            existing.setPattern(newRestrictionPattern);
+        } else {
+            if (newRestrictionPattern != null){
+                for (XsdPattern patternElem : newRestrictionPattern){
+                    if (existingPattern.stream().noneMatch(existingPatternElem -> existingPatternElem.getValue().equals(patternElem.getValue()))){
+                        existingPattern.add(patternElem);
+                    }
+                }
+            }
+        }
     }
 
     /**
@@ -283,8 +302,7 @@ private void updateExistingRestrictionEnumerations(XsdRestriction existing, XsdR
      * @return True if an overlap between the restrictions occur, false if it doesn't occur.
      */
     private boolean existsRestrictionOverlap(XsdRestriction existing, XsdRestriction newRestriction) {
-        return hasDifferentValue(existing.getPattern(), newRestriction.getPattern()) ||
-               hasDifferentValue(existing.getWhiteSpace(), newRestriction.getWhiteSpace()) ||
+        return hasDifferentValue(existing.getWhiteSpace(), newRestriction.getWhiteSpace()) ||
                hasDifferentValue(existing.getTotalDigits(), newRestriction.getTotalDigits()) ||
                hasDifferentValue(existing.getFractionDigits(), newRestriction.getFractionDigits()) ||
                hasDifferentValue(existing.getMaxExclusive(), newRestriction.getMaxExclusive()) ||
diff --git a/src/main/java/org/xmlet/xsdparser/xsdelements/visitors/XsdRestrictionsVisitor.java b/src/main/java/org/xmlet/xsdparser/xsdelements/visitors/XsdRestrictionsVisitor.java
index bec087a..19892fa 100644
--- a/src/main/java/org/xmlet/xsdparser/xsdelements/visitors/XsdRestrictionsVisitor.java
+++ b/src/main/java/org/xmlet/xsdparser/xsdelements/visitors/XsdRestrictionsVisitor.java
@@ -107,7 +107,7 @@ public void visit(XsdMinLength element) {
     public void visit(XsdPattern element) {
         super.visit(element);
 
-        owner.setPattern(element);
+        owner.add(element);
     }
 
     @Override