diff --git a/rules/DeadCode/Rector/Assign/RemoveUnusedAssignVariableRector.php b/rules/DeadCode/Rector/Assign/RemoveUnusedAssignVariableRector.php
index 97dff1e7d12..97106ba3f32 100644
--- a/rules/DeadCode/Rector/Assign/RemoveUnusedAssignVariableRector.php
+++ b/rules/DeadCode/Rector/Assign/RemoveUnusedAssignVariableRector.php
@@ -96,6 +96,13 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        // @see https://github.com/rectorphp/rector/issues/6655
+        // verify current statement is a Node before removing or use its Assign Expr
+        $currentStatement = $node->getAttribute(AttributeKey::CURRENT_STATEMENT);
+        if (! $currentStatement instanceof Node) {
+            return null;
+        }
+
         // is scalar assign? remove whole
         if (! $this->sideEffectNodeDetector->detect($node->expr)) {
             $this->removeNode($node);
diff --git a/tests/Issues/Issue6655/Fixture/fixture.php.inc b/tests/Issues/Issue6655/Fixture/fixture.php.inc
new file mode 100644
index 00000000000..7c00207faf6
--- /dev/null
+++ b/tests/Issues/Issue6655/Fixture/fixture.php.inc
@@ -0,0 +1,23 @@
+<?php
+
+function getRes(): string
+{
+    if ('a' !== 'b') {
+        $res = "a";
+    } else {
+        $res = "b";
+    }
+
+    return $res;
+}
+?>
+-----
+<?php
+
+function getRes(): string
+{
+    $res = 'a' !== 'b' ? "a" : "b";
+
+    return $res;
+}
+?>
diff --git a/tests/Issues/Issue6655/SimplifyIfElseAndRemoveUnusedAssignVariableTest.php b/tests/Issues/Issue6655/SimplifyIfElseAndRemoveUnusedAssignVariableTest.php
new file mode 100644
index 00000000000..31f0195e516
--- /dev/null
+++ b/tests/Issues/Issue6655/SimplifyIfElseAndRemoveUnusedAssignVariableTest.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Core\Tests\Issues\Issue6655;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+/**
+ * @see https://github.com/rectorphp/rector/issues/6655
+ */
+final class SimplifyIfElseAndRemoveUnusedAssignVariableTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    /**
+     * @return Iterator<SmartFileInfo>
+     */
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}
diff --git a/tests/Issues/Issue6655/config/configured_rule.php b/tests/Issues/Issue6655/config/configured_rule.php
new file mode 100644
index 00000000000..958d5cf320a
--- /dev/null
+++ b/tests/Issues/Issue6655/config/configured_rule.php
@@ -0,0 +1,12 @@
+<?php
+
+use Rector\DeadCode\Rector\Assign\RemoveUnusedAssignVariableRector;
+use Rector\CodeQuality\Rector\If_\SimplifyIfElseToTernaryRector;
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+
+return static function (ContainerConfigurator $containerConfigurator): void {
+    $services = $containerConfigurator->services();
+
+    $services->set(SimplifyIfElseToTernaryRector::class);
+    $services->set(RemoveUnusedAssignVariableRector::class);
+};