diff --git a/mlir/lib/IR/AsmPrinter.cpp b/mlir/lib/IR/AsmPrinter.cpp
--- a/mlir/lib/IR/AsmPrinter.cpp
+++ b/mlir/lib/IR/AsmPrinter.cpp
@@ -2718,7 +2718,10 @@
       if (auto opPrinter = dialect->getOperationPrinter(op)) {
         // Print the op name first.
         StringRef name = op->getName().getStringRef();
-        name.consume_front((defaultDialectStack.back() + ".").str());
+        // Only drop the default dialect prefix when it cannot lead to
+        // ambiguities.
+        if (name.count('.') == 1)
+          name.consume_front((defaultDialectStack.back() + ".").str());
         printEscapedString(name, os);
         // Print the rest of the op now.
         opPrinter(op, *this);
diff --git a/mlir/lib/IR/Operation.cpp b/mlir/lib/IR/Operation.cpp
--- a/mlir/lib/IR/Operation.cpp
+++ b/mlir/lib/IR/Operation.cpp
@@ -624,11 +624,12 @@
   }
 }
 
-/// Print an operation name, eliding the dialect prefix if necessary.
+/// Print an operation name, eliding the dialect prefix if necessary and doesn't
+/// lead to ambiguities.
 void OpState::printOpName(Operation *op, OpAsmPrinter &p,
                           StringRef defaultDialect) {
   StringRef name = op->getName().getStringRef();
-  if (name.startswith((defaultDialect + ".").str()))
+  if (name.startswith((defaultDialect + ".").str()) && name.count('.') == 1)
     name = name.drop_front(defaultDialect.size() + 1);
   p.getStream() << name;
 }
diff --git a/mlir/test/IR/parser.mlir b/mlir/test/IR/parser.mlir
--- a/mlir/test/IR/parser.mlir
+++ b/mlir/test/IR/parser.mlir
@@ -1282,6 +1282,14 @@
     // example.
     // CHECK:  "test.op_with_attr"() {test.attr = "test.value"} : () -> ()
     "test.op_with_attr"() {test.attr = "test.value"} : () -> ()
+    // Verify that the prefix is not stripped when it can lead to ambiguity.
+    // CHECK: test.op.with_dot_in_name
+    test.op.with_dot_in_name
+    // This is an unregistered operation, the printing/parsing is handled by the
+    // dialect, and the dialect prefix should not be stripped while printing
+    // because of potential ambiguity.
+    // CHECK: test.dialect_custom_printer.with.dot
+    test.dialect_custom_printer.with.dot
     "test.terminator"() : ()->()
   }
   // The same operation outside of the region does not have an func. prefix.
diff --git a/mlir/test/lib/Dialect/Test/TestDialect.cpp b/mlir/test/lib/Dialect/Test/TestDialect.cpp
--- a/mlir/test/lib/Dialect/Test/TestDialect.cpp
+++ b/mlir/test/lib/Dialect/Test/TestDialect.cpp
@@ -371,6 +371,11 @@
       return parser.parseKeyword("custom_format_fallback");
     }};
   }
+  if (opName == "test.dialect_custom_printer.with.dot") {
+    return ParseOpHook{[](OpAsmParser &parser, OperationState &state) {
+      return ParseResult::success();
+    }};
+  }
   return None;
 }
 
diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -810,6 +810,12 @@
   let assemblyFormat = "regions attr-dict-with-keyword";
 }
 
+// This is used to test that the default dialect is not elided when printing an
+// op with dots in the name to avoid parsing ambiguity.
+def OpWithDotInNameOp : TEST_Op<"op.with_dot_in_name"> {
+  let assemblyFormat = "attr-dict";
+}
+
 // This is used to test the OpAsmOpInterface::getAsmBlockName() feature:
 // blocks nested in a region under this op will have a name defined by the
 // interface.