diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.td b/flang/include/flang/Optimizer/Dialect/FIROps.td
--- a/flang/include/flang/Optimizer/Dialect/FIROps.td
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.td
@@ -2334,10 +2334,10 @@
 
     ```mlir
       // fir.dispatch with the `nopass` attribute.
-      %r = fir.dispatch "methodA"(%o) : (!fir.class<T>) -> i32 {nopass}
+      %r = fir.dispatch "methodA"(%o : !fir.class<T>) -> i32 {nopass}
 
       // fir.dispatch with the `pass_arg_pos` attribute.
-      %r = fir.dispatch "methodA"(%o, %o) : (!fir.class<T>, !fir.class<T>) -> i32 {pass_arg_pos = 0 : i32}
+      %r = fir.dispatch "methodA"(%o : !fir.class<T>) (%o : !fir.class<T>) -> i32 {pass_arg_pos = 0 : i32}
     ```
   }];
 
@@ -2349,11 +2349,14 @@
     OptionalAttr<I32Attr>:$pass_arg_pos
   );
 
-  let results = (outs Variadic<AnyType>);
+  let results = (outs Variadic<AnyType>:$results);
 
   let hasVerifier = 1;
 
-  let hasCustomAssemblyFormat = 1;
+  let assemblyFormat = [{
+    $method `(` $object `:` qualified(type($object)) `)`
+    ( `(` $args^ `:` type($args) `)` )? (`->` type($results)^)? attr-dict
+  }];
 
   let extraClassDeclaration = [{
     mlir::FunctionType getFunctionType();
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -1062,47 +1062,6 @@
                                  getResultTypes());
 }
 
-mlir::ParseResult fir::DispatchOp::parse(mlir::OpAsmParser &parser,
-                                         mlir::OperationState &result) {
-  mlir::FunctionType calleeType;
-  llvm::SmallVector<mlir::OpAsmParser::UnresolvedOperand> operands;
-  auto calleeLoc = parser.getNameLoc();
-  llvm::StringRef calleeName;
-  if (failed(parser.parseOptionalKeyword(&calleeName))) {
-    mlir::StringAttr calleeAttr;
-    if (parser.parseAttribute(calleeAttr,
-                              fir::DispatchOp::getMethodAttrNameStr(),
-                              result.attributes))
-      return mlir::failure();
-  } else {
-    result.addAttribute(fir::DispatchOp::getMethodAttrNameStr(),
-                        parser.getBuilder().getStringAttr(calleeName));
-  }
-  if (parser.parseOperandList(operands, mlir::OpAsmParser::Delimiter::Paren) ||
-      parser.parseColonType(calleeType) ||
-      parser.addTypesToList(calleeType.getResults(), result.types) ||
-      parser.resolveOperands(operands, calleeType.getInputs(), calleeLoc,
-                             result.operands) ||
-      parser.parseOptionalAttrDict(result.attributes))
-    return mlir::failure();
-  return mlir::success();
-}
-
-void fir::DispatchOp::print(mlir::OpAsmPrinter &p) {
-  p << ' ' << getMethodAttr() << '(';
-  p.printOperand(getObject());
-  if (!getArgs().empty()) {
-    p << ", ";
-    p.printOperands(getArgs());
-  }
-  p << ") : ";
-  p.printFunctionalType(getOperation()->getOperandTypes(),
-                        getOperation()->getResultTypes());
-  p.printOptionalAttrDict(getOperation()->getAttrs(),
-                          {mlir::SymbolTable::getSymbolAttrName(),
-                           fir::DispatchOp::getMethodAttrNameStr()});
-}
-
 //===----------------------------------------------------------------------===//
 // DispatchTableOp
 //===----------------------------------------------------------------------===//
diff --git a/flang/test/Fir/Todo/dispatch.fir b/flang/test/Fir/Todo/dispatch.fir
--- a/flang/test/Fir/Todo/dispatch.fir
+++ b/flang/test/Fir/Todo/dispatch.fir
@@ -5,6 +5,6 @@
 
 func.func @dispatch(%arg0: !fir.class<!fir.type<derived3{f:f32}>>) {
 // CHECK: not yet implemented: fir.class type conversion
-  %0 = fir.dispatch "method"(%arg0) : (!fir.class<!fir.type<derived3{f:f32}>>) -> i32
+  %0 = fir.dispatch "method"(%arg0 : !fir.class<!fir.type<derived3{f:f32}>>) -> i32
   return
 }
diff --git a/flang/test/Fir/fir-ops.fir b/flang/test/Fir/fir-ops.fir
--- a/flang/test/Fir/fir-ops.fir
+++ b/flang/test/Fir/fir-ops.fir
@@ -115,13 +115,13 @@
   %26 = fir.len_param_index f, !fir.type<derived3{f:f32}>
 
 // CHECK: [[VAL_31:%.*]] = fir.call @box3() : () -> !fir.class<!fir.type<derived3{f:f32}>>
-// CHECK: [[VAL_32:%.*]] = fir.dispatch "method"([[VAL_31]]) : (!fir.class<!fir.type<derived3{f:f32}>>) -> i32
+// CHECK: [[VAL_32:%.*]] = fir.dispatch "method"([[VAL_31]] : !fir.class<!fir.type<derived3{f:f32}>>) -> i32
 // CHECK: [[VAL_33:%.*]] = fir.convert [[VAL_32]] : (i32) -> i64
 // CHECK: [[VAL_34:%.*]] = fir.gentypedesc !fir.type<x>
 // CHECK: fir.call @user_tdesc([[VAL_34]]) : (!fir.tdesc<!fir.type<x>>) -> ()
 // CHECK: [[VAL_35:%.*]] = fir.no_reassoc [[VAL_33]] : i64
   %27 = fir.call @box3() : () -> !fir.class<!fir.type<derived3{f:f32}>>
-  %28 = fir.dispatch "method"(%27) : (!fir.class<!fir.type<derived3{f:f32}>>) -> i32
+  %28 = fir.dispatch "method"(%27 : !fir.class<!fir.type<derived3{f:f32}>>) -> i32
   %29 = fir.convert %28 : (i32) -> i64
   %30 = fir.gentypedesc !fir.type<x>
   fir.call @user_tdesc(%30) : (!fir.tdesc<!fir.type<x>>) -> ()
@@ -310,11 +310,11 @@
 // CHECK: ^bb5:
 // CHECK: [[VAL_99:%.*]] = arith.constant 0 : i32
 // CHECK: [[VAL_100:%.*]] = fir.call @get_method_box() : () -> !fir.class<!fir.type<derived3{f:f32}>>
-// CHECK: fir.dispatch "method"([[VAL_100]]) : (!fir.class<!fir.type<derived3{f:f32}>>) -> ()
+// CHECK: fir.dispatch "method"([[VAL_100]] : !fir.class<!fir.type<derived3{f:f32}>>)
 ^bb5 :
   %zero = arith.constant 0 : i32
   %7 = fir.call @get_method_box() : () -> !fir.class<!fir.type<derived3{f:f32}>>
-  fir.dispatch method(%7) : (!fir.class<!fir.type<derived3{f:f32}>>) -> ()
+  fir.dispatch "method"(%7 : !fir.class<!fir.type<derived3{f:f32}>>)
 
 // CHECK: return [[VAL_99]] : i32
 // CHECK: }
@@ -809,13 +809,13 @@
 func.func private @dispatch(%arg0: !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, %arg1: i32) -> () {
   // CHECK-LABEL: func.func private @dispatch(
   // CHECK-SAME: %[[CLASS:.*]]: !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, %[[INTARG:.*]]: i32)
-  fir.dispatch "proc1"(%arg0, %arg0) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {pass_arg_pos = 0 : i32}
-  // CHECK: fir.dispatch "proc1"(%[[CLASS]], %[[CLASS]]) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {pass_arg_pos = 0 : i32}
+  fir.dispatch "proc1"(%arg0 : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) (%arg0 : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
+  // CHECK: fir.dispatch "proc1"(%[[CLASS]] : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) (%[[CLASS]] : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
 
-  fir.dispatch "proc2"(%arg0) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {nopass}
-  // CHECK: fir.dispatch "proc2"(%[[CLASS]]) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {nopass}
+  fir.dispatch "proc2"(%arg0 : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>)
+  // CHECK: fir.dispatch "proc2"(%[[CLASS]] : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>)
 
-  fir.dispatch "proc3"(%arg0, %arg1, %arg0) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, i32, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {pass_arg_pos = 1 : i32}
-  // CHECK: fir.dispatch "proc3"(%[[CLASS]], %[[INTARG]], %[[CLASS]]) : (!fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>, i32, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) -> () {pass_arg_pos = 1 : i32}
+  fir.dispatch "proc3"(%arg0 : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) (%arg1, %arg0 : i32, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) {pass_arg_pos = 1 : i32}
+  // CHECK: fir.dispatch "proc3"(%[[CLASS]] : !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) (%[[INTARG]], %[[CLASS]] : i32, !fir.class<!fir.type<dispatch_derived1{a:i32,b:i32}>>) {pass_arg_pos = 1 : i32}
   return
 }
diff --git a/flang/test/Fir/invalid.fir b/flang/test/Fir/invalid.fir
--- a/flang/test/Fir/invalid.fir
+++ b/flang/test/Fir/invalid.fir
@@ -761,7 +761,7 @@
 
 func.func private @dispatch(%arg0: !fir.class<!fir.type<derived{a:i32,b:i32}>>) -> () {
   // expected-error@+1 {{'fir.dispatch' op nopass and pass_arg_idx are mutually exclusive}}
-  fir.dispatch "proc1"(%arg0, %arg0) : (!fir.class<!fir.type<derived{a:i32,b:i32}>>, !fir.class<!fir.type<derived{a:i32,b:i32}>>) -> () {nopass, pass_arg_pos = 0 : i32}
+  fir.dispatch "proc1"(%arg0 : !fir.class<!fir.type<derived{a:i32,b:i32}>>) (%arg0 : !fir.class<!fir.type<derived{a:i32,b:i32}>>) {nopass, pass_arg_pos = 0 : i32}
   return
 }
 
@@ -769,7 +769,7 @@
 
 func.func private @dispatch(%arg0: !fir.class<!fir.type<derived{a:i32,b:i32}>>) -> () {
   // expected-error@+1 {{'fir.dispatch' op pass_arg_pos must be smaller than the number of operands}}
-  fir.dispatch "proc1"(%arg0, %arg0) : (!fir.class<!fir.type<derived{a:i32,b:i32}>>, !fir.class<!fir.type<derived{a:i32,b:i32}>>) -> () {pass_arg_pos = 1 : i32}
+  fir.dispatch "proc1"(%arg0 : !fir.class<!fir.type<derived{a:i32,b:i32}>>) (%arg0 : !fir.class<!fir.type<derived{a:i32,b:i32}>>) {pass_arg_pos = 1 : i32}
   return
 }
 
@@ -777,6 +777,6 @@
 
 func.func private @dispatch(%arg0: !fir.class<!fir.type<derived{a:i32,b:i32}>>, %arg1: i32) -> () {
   // expected-error@+1 {{'fir.dispatch' op pass_arg_pos must be a polymorphic operand}}
-  fir.dispatch "proc1"(%arg0, %arg0, %arg1) : (!fir.class<!fir.type<derived{a:i32,b:i32}>>, !fir.class<!fir.type<derived{a:i32,b:i32}>>, i32) -> () {pass_arg_pos = 1 : i32}
+  fir.dispatch "proc1"(%arg0 : !fir.class<!fir.type<derived{a:i32,b:i32}>>) (%arg0, %arg1 : !fir.class<!fir.type<derived{a:i32,b:i32}>>, i32) {pass_arg_pos = 1 : i32}
   return
 }