diff --git a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandard.cpp b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandard.cpp
--- a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandard.cpp
+++ b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandard.cpp
@@ -38,6 +38,20 @@
   }
 };
 
+class GetSizeOpConverter : public OpConversionPattern<GetSizeOp> {
+public:
+  using OpConversionPattern<GetSizeOp>::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(GetSizeOp op, ArrayRef<Value> operands,
+                  ConversionPatternRewriter &rewriter) const override {
+    GetSizeOp::Adaptor transformed(operands);
+    rewriter.replaceOpWithNewOp<DimOp>(op.getOperation(), transformed.shape(),
+                                       0);
+    return success();
+  }
+};
+
 class IndexToSizeOpConversion : public OpConversionPattern<IndexToSizeOp> {
 public:
   using OpConversionPattern<IndexToSizeOp>::OpConversionPattern;
@@ -133,6 +147,7 @@
       BinaryOpConversion<AddOp, AddIOp>,
       BinaryOpConversion<MulOp, MulIOp>,
       ConstSizeOpConverter,
+      GetSizeOpConverter,
       IndexToSizeOpConversion,
       SizeToIndexOpConversion>(ctx);
   // clang-format on
diff --git a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td
--- a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td
+++ b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td
@@ -9,4 +9,3 @@
 def ToExtentTensorOpConversion : Pat<
     (Shape_ToExtentTensorOp $input),
     (replaceWithValue $input)>;
-
diff --git a/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir b/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir
--- a/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir
+++ b/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir
@@ -86,3 +86,17 @@
 }
 // CHECK: %[[C1:.*]] = constant 1 : index
 // CHECK: return %[[C1]] : index
+
+// -----
+
+// Convert `get_size` to `dim` of the first dimension.
+// CHECK-LABEL: @get_size
+// CHECK-SAME: (%[[SHAPE:.*]]: tensor<?xindex>) -> index
+func @get_size(%shape : !shape.shape) -> !shape.size {
+  // CHECK-DAG: %[[C0:.*]] = constant 0 : index
+  // CHECK-DAG: %[[RESULT:.*]] = dim %[[SHAPE]], %[[C0]]
+  // CHECK-DAG: return %[[RESULT]] : index
+  %size = shape.get_size %shape
+  return %size : !shape.size
+}
+