diff --git a/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td b/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
index 2f4517ddfe754..c689b7e46ea9e 100644
--- a/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
+++ b/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
@@ -2557,6 +2557,12 @@ def OpenACC_LoopOp : OpenACC_Op<"loop",
     device-type-aware getter methods. When modifying these operands, the
     corresponding `device_type` attributes must be updated to maintain
     consistency between operands and their target device types.
+
+    The `unstructured` attribute indicates that the loops inside the OpenACC
+    construct contain early exits and cannot be lowered to structured MLIR
+    operations. When this flag is set, the acc.loop should have no induction
+    variables and the loop must be implemented via explicit control flow
+    inside its body.
   }];
 
   let arguments = (ins
@@ -2590,7 +2596,8 @@ def OpenACC_LoopOp : OpenACC_Op<"loop",
       OptionalAttr<SymbolRefArrayAttr>:$firstprivatizationRecipes,
       Variadic<AnyType>:$reductionOperands,
       OptionalAttr<SymbolRefArrayAttr>:$reductionRecipes,
-      OptionalAttr<OpenACC_CombinedConstructsAttr>:$combined
+      OptionalAttr<OpenACC_CombinedConstructsAttr>:$combined,
+      UnitAttr:$unstructured
   );
 
   let results = (outs Variadic<AnyType>:$results);
diff --git a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
index 35eba724a9059..b2f1d840f3bca 100644
--- a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
+++ b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
@@ -3068,8 +3068,12 @@ LogicalResult acc::LoopOp::verify() {
   if (getRegion().empty())
     return emitError("expected non-empty body.");
 
-  // When it is container-like - it is expected to hold a loop-like operation.
-  if (isContainerLike()) {
+  if (getUnstructured()) {
+    if (!isContainerLike())
+      return emitError(
+          "unstructured acc.loop must not have induction variables");
+  } else if (isContainerLike()) {
+    // When it is container-like - it is expected to hold a loop-like operation.
     // Obtain the maximum collapse count - we use this to check that there
     // are enough loops contained.
     uint64_t collapseCount = getCollapseValue().value_or(1);
diff --git a/mlir/test/Dialect/OpenACC/invalid.mlir b/mlir/test/Dialect/OpenACC/invalid.mlir
index 26b63fbe182ea..0e75894eaeceb 100644
--- a/mlir/test/Dialect/OpenACC/invalid.mlir
+++ b/mlir/test/Dialect/OpenACC/invalid.mlir
@@ -492,6 +492,15 @@ func.func @fct1(%0 : !llvm.ptr) -> () {
 
 // -----
 
+%i1 = arith.constant 1 : i32
+%i2 = arith.constant 10 : i32
+// expected-error@+1 {{unstructured acc.loop must not have induction variables}}
+acc.loop control(%iv : i32) = (%i1 : i32) to (%i2 : i32) step (%i1 : i32) {
+  acc.yield
+} attributes {independent = [#acc.device_type<none>], unstructured}
+
+// -----
+
 // expected-error@+1 {{expect at least one of num, dim or static values}}
 acc.loop gang({}) {
   "test.openacc_dummy_op"() : () -> ()
diff --git a/mlir/test/Dialect/OpenACC/ops.mlir b/mlir/test/Dialect/OpenACC/ops.mlir
index 042ee2503cb95..df8ab9b7dd239 100644
--- a/mlir/test/Dialect/OpenACC/ops.mlir
+++ b/mlir/test/Dialect/OpenACC/ops.mlir
@@ -2143,6 +2143,20 @@ func.func @acc_loop_container() {
 
 // -----
 
+func.func @acc_unstructured_loop() {
+  acc.loop {
+    acc.yield
+  } attributes {independent = [#acc.device_type<none>], unstructured}
+  return
+}
+
+// CHECK-LABEL: func.func @acc_unstructured_loop
+// CHECK:       acc.loop
+// CHECK:         acc.yield
+// CHECK:       } attributes {independent = [#acc.device_type<none>], unstructured}
+
+// -----
+
 // Test private recipe with data bounds for array slicing
 acc.private.recipe @privatization_memref_slice : memref<10x10xf32> init {
 ^bb0(%arg0: memref<10x10xf32>, %bounds0: !acc.data_bounds_ty, %bounds1: !acc.data_bounds_ty):