diff --git a/mlir/lib/Conversion/GPUCommon/ConvertLaunchFuncToRuntimeCalls.cpp b/mlir/lib/Conversion/GPUCommon/ConvertLaunchFuncToRuntimeCalls.cpp
--- a/mlir/lib/Conversion/GPUCommon/ConvertLaunchFuncToRuntimeCalls.cpp
+++ b/mlir/lib/Conversion/GPUCommon/ConvertLaunchFuncToRuntimeCalls.cpp
@@ -294,7 +294,7 @@
     Operation *op, ArrayRef<Value> operands,
     ConversionPatternRewriter &rewriter) const {
   if (cast<gpu::WaitOp>(op).asyncToken())
-    return failure(); // The gpu.wait is async.
+    return rewriter.notifyMatchFailure(op, "Cannot convert async op.");
 
   Location loc = op->getLoc();
 
@@ -317,7 +317,7 @@
     Operation *op, ArrayRef<Value> operands,
     ConversionPatternRewriter &rewriter) const {
   if (!cast<gpu::WaitOp>(op).asyncToken())
-    return failure(); // The gpu.wait is not async.
+    return rewriter.notifyMatchFailure(op, "Can only convert async op.");
 
   Location loc = op->getLoc();
 
@@ -445,6 +445,11 @@
         op, "Cannot convert if operands aren't of LLVM type.");
 
   auto launchOp = cast<gpu::LaunchFuncOp>(op);
+
+  if (launchOp.asyncDependencies().size() > 1)
+    return rewriter.notifyMatchFailure(
+        op, "Cannot convert with more than one async dependency.");
+
   Location loc = launchOp.getLoc();
 
   // Create an LLVM global with CUBIN extracted from the kernel annotation and
@@ -475,8 +480,11 @@
       loc, rewriter, {module.getResult(0), kernelName});
   auto zero = rewriter.create<LLVM::ConstantOp>(loc, llvmInt32Type,
                                                 rewriter.getI32IntegerAttr(0));
-  // Grab the global stream needed for execution.
-  auto stream = streamCreateCallBuilder.create(loc, rewriter, {});
+  auto adaptor = gpu::LaunchFuncOpAdaptor(operands, op->getAttrDictionary());
+  Value stream =
+      adaptor.asyncDependencies().empty()
+          ? streamCreateCallBuilder.create(loc, rewriter, {}).getResult(0)
+          : adaptor.asyncDependencies().front();
   // Create array of pointers to kernel arguments.
   auto kernelParams = generateParamsArray(launchOp, operands, rewriter);
   auto nullpointer = rewriter.create<LLVM::NullOp>(loc, llvmPointerPointerType);
@@ -484,13 +492,19 @@
       loc, rewriter,
       {function.getResult(0), launchOp.gridSizeX(), launchOp.gridSizeY(),
        launchOp.gridSizeZ(), launchOp.blockSizeX(), launchOp.blockSizeY(),
-       launchOp.blockSizeZ(), zero, /* sharedMemBytes */
-       stream.getResult(0),         /* stream */
-       kernelParams,                /* kernel params */
-       nullpointer /* extra */});
-  streamSynchronizeCallBuilder.create(loc, rewriter, stream.getResult(0));
+       launchOp.blockSizeZ(), /*sharedMemBytes=*/zero, stream, kernelParams,
+       /*extra=*/nullpointer});
+
+  if (launchOp.asyncToken()) {
+    // Async launch: reuse stream.
+    rewriter.replaceOp(op, {stream});
+  } else {
+    // Synchronize with host and destroy stream.
+    streamSynchronizeCallBuilder.create(loc, rewriter, stream);
+    streamDestroyCallBuilder.create(loc, rewriter, stream);
+    rewriter.eraseOp(op);
+  }
 
-  rewriter.eraseOp(op);
   return success();
 }