diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -465,6 +465,26 @@
   }
 };
 
+/// Lower `fir.box_tdesc` to the sequence of operation to extract the type
+/// descriptor from the box.
+struct BoxTypeDescOpConversion : public FIROpConversion<fir::BoxTypeDescOp> {
+  using FIROpConversion::FIROpConversion;
+
+  mlir::LogicalResult
+  matchAndRewrite(fir::BoxTypeDescOp boxtypedesc, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+    mlir::Value box = adaptor.getOperands()[0];
+    auto loc = boxtypedesc.getLoc();
+    mlir::Type typeTy =
+        fir::getDescFieldTypeModel<kTypePosInBox>()(boxtypedesc.getContext());
+    auto result = getValueFromBox(loc, box, typeTy, rewriter, kTypePosInBox);
+    auto typePtrTy = mlir::LLVM::LLVMPointerType::get(typeTy);
+    rewriter.replaceOpWithNewOp<mlir::LLVM::IntToPtrOp>(boxtypedesc, typePtrTy,
+                                                        result);
+    return success();
+  }
+};
+
 // `fir.call` -> `llvm.call`
 struct CallOpConversion : public FIROpConversion<fir::CallOp> {
   using FIROpConversion::FIROpConversion;
@@ -1513,16 +1533,17 @@
         AbsentOpConversion, AddcOpConversion, AddrOfOpConversion,
         AllocaOpConversion, BoxAddrOpConversion, BoxDimsOpConversion,
         BoxEleSizeOpConversion, BoxIsAllocOpConversion, BoxIsArrayOpConversion,
-        BoxIsPtrOpConversion, BoxRankOpConversion, CallOpConversion,
-        ConvertOpConversion, DispatchOpConversion, DispatchTableOpConversion,
-        DTEntryOpConversion, DivcOpConversion, EmboxCharOpConversion,
-        ExtractValueOpConversion, HasValueOpConversion, GlobalLenOpConversion,
-        GlobalOpConversion, InsertOnRangeOpConversion, InsertValueOpConversion,
-        IsPresentOpConversion, LoadOpConversion, NegcOpConversion,
-        MulcOpConversion, SelectCaseOpConversion, SelectOpConversion,
-        SelectRankOpConversion, SelectTypeOpConversion, StoreOpConversion,
-        SubcOpConversion, UnboxCharOpConversion, UndefOpConversion,
-        UnreachableOpConversion, ZeroOpConversion>(typeConverter);
+        BoxIsPtrOpConversion, BoxRankOpConversion, BoxTypeDescOpConversion,
+        CallOpConversion, ConvertOpConversion, DispatchOpConversion,
+        DispatchTableOpConversion, DTEntryOpConversion, DivcOpConversion,
+        EmboxCharOpConversion, ExtractValueOpConversion, HasValueOpConversion,
+        GlobalLenOpConversion, GlobalOpConversion, InsertOnRangeOpConversion,
+        InsertValueOpConversion, IsPresentOpConversion, LoadOpConversion,
+        NegcOpConversion, MulcOpConversion, SelectCaseOpConversion,
+        SelectOpConversion, SelectRankOpConversion, SelectTypeOpConversion,
+        StoreOpConversion, SubcOpConversion, UnboxCharOpConversion,
+        UndefOpConversion, UnreachableOpConversion, ZeroOpConversion>(
+        typeConverter);
     mlir::populateStdToLLVMConversionPatterns(typeConverter, pattern);
     mlir::arith::populateArithmeticToLLVMConversionPatterns(typeConverter,
                                                             pattern);
diff --git a/flang/test/Fir/convert-to-llvm.fir b/flang/test/Fir/convert-to-llvm.fir
--- a/flang/test/Fir/convert-to-llvm.fir
+++ b/flang/test/Fir/convert-to-llvm.fir
@@ -1200,3 +1200,20 @@
 // CHECK-NEXT:  %[[ptr:.*]] = llvm.mlir.null : !llvm.ptr<i64>
 // CHECK-NEXT:  %[[ret_val:.*]] = llvm.call @is_present(%[[ptr]]) : (!llvm.ptr<i64>) -> i1
 // CHECK-NEXT:  llvm.return %[[ret_val]] : i1
+
+// -----
+
+// Test `fir.box_tdesc` conversion.
+
+func @box_tdesc(%arg0: !fir.box<f64>) {
+  %0 = fir.box_tdesc %arg0 : (!fir.box<f64>) -> !fir.tdesc<f64>
+  return
+}
+
+// CHECK-LABEL: llvm.func @box_tdesc(
+// CHECK-SAME:                       %[[ARG0:.*]]: !llvm.ptr<struct<(ptr<f64>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}})>>) {
+// CHECK:         %[[C0:.*]] = llvm.mlir.constant(0 : i32) : i32
+// CHECK:         %[[TYPE_POS:.*]] = llvm.mlir.constant(4 : i32) : i32
+// CHECK:         %[[GEP:.*]] = llvm.getelementptr %[[ARG0]][%[[C0]], %[[TYPE_POS]]] : (!llvm.ptr<struct<(ptr<f64>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}})>>, i32, i32) -> !llvm.ptr<i8>
+// CHECK:         %[[LOAD:.*]] = llvm.load %[[GEP]] : !llvm.ptr<i{{.*}}>
+// CHECK:         %{{.*}} = llvm.inttoptr %[[LOAD]] : i{{.*}} to !llvm.ptr<i{{.*}}>