diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
--- a/flang/lib/Lower/ConvertExpr.cpp
+++ b/flang/lib/Lower/ConvertExpr.cpp
@@ -570,12 +570,36 @@
 
   template <int KIND>
   ExtValue genval(const Fortran::evaluate::Not<KIND> &op) {
-    TODO(getLoc(), "genval Not<KIND>");
+    mlir::Value logical = genunbox(op.left());
+    mlir::Value one = genBoolConstant(true);
+    mlir::Value val =
+        builder.createConvert(getLoc(), builder.getI1Type(), logical);
+    return builder.create<mlir::arith::XOrIOp>(getLoc(), val, one);
   }
 
   template <int KIND>
   ExtValue genval(const Fortran::evaluate::LogicalOperation<KIND> &op) {
-    TODO(getLoc(), "genval LogicalOperation<KIND>");
+    mlir::IntegerType i1Type = builder.getI1Type();
+    mlir::Value slhs = genunbox(op.left());
+    mlir::Value srhs = genunbox(op.right());
+    mlir::Value lhs = builder.createConvert(getLoc(), i1Type, slhs);
+    mlir::Value rhs = builder.createConvert(getLoc(), i1Type, srhs);
+    switch (op.logicalOperator) {
+    case Fortran::evaluate::LogicalOperator::And:
+      return createBinaryOp<mlir::arith::AndIOp>(lhs, rhs);
+    case Fortran::evaluate::LogicalOperator::Or:
+      return createBinaryOp<mlir::arith::OrIOp>(lhs, rhs);
+    case Fortran::evaluate::LogicalOperator::Eqv:
+      return createCompareOp<mlir::arith::CmpIOp>(
+          mlir::arith::CmpIPredicate::eq, lhs, rhs);
+    case Fortran::evaluate::LogicalOperator::Neqv:
+      return createCompareOp<mlir::arith::CmpIOp>(
+          mlir::arith::CmpIPredicate::ne, lhs, rhs);
+    case Fortran::evaluate::LogicalOperator::Not:
+      // lib/evaluate expression for .NOT. is Fortran::evaluate::Not<KIND>.
+      llvm_unreachable(".NOT. is not a binary operator");
+    }
+    llvm_unreachable("unhandled logical operation");
   }
 
   /// Convert a scalar literal constant to IR.
diff --git a/flang/test/Lower/logical-operations.f90 b/flang/test/Lower/logical-operations.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/logical-operations.f90
@@ -0,0 +1,65 @@
+! RUN: bbc %s -o "-" | FileCheck %s
+
+! Test logical intrinsic operation lowering to fir.
+
+! CHECK-LABEL:eqv0_test
+LOGICAL(1) FUNCTION eqv0_test(x0, x1)
+LOGICAL(1) :: x0
+LOGICAL(1) :: x1
+! CHECK-DAG:[[reg1:%[0-9]+]] = fir.load %arg0
+! CHECK-DAG:[[reg2:%[0-9]+]] = fir.load %arg1
+! CHECK-DAG:[[reg3:%[0-9]+]] = fir.convert [[reg1]] {{.*}} -> i1
+! CHECK-DAG:[[reg4:%[0-9]+]] = fir.convert [[reg2]] {{.*}} -> i1
+! CHECK:[[reg5:%[0-9]+]] = arith.cmpi eq, [[reg3]], [[reg4]]
+! CHECK:fir.convert [[reg5]] {{.*}} -> !fir.logical<1>
+eqv0_test = x0 .EQV. x1
+END FUNCTION
+
+! CHECK-LABEL:neqv1_test
+LOGICAL(1) FUNCTION neqv1_test(x0, x1)
+LOGICAL(1) :: x0
+LOGICAL(1) :: x1
+! CHECK-DAG:[[reg1:%[0-9]+]] = fir.load %arg0
+! CHECK-DAG:[[reg2:%[0-9]+]] = fir.load %arg1
+! CHECK-DAG:[[reg3:%[0-9]+]] = fir.convert [[reg1]] {{.*}} -> i1
+! CHECK-DAG:[[reg4:%[0-9]+]] = fir.convert [[reg2]] {{.*}} -> i1
+! CHECK:[[reg5:%[0-9]+]] = arith.cmpi ne, [[reg3]], [[reg4]]
+! CHECK:fir.convert [[reg5]] {{.*}} -> !fir.logical<1>
+neqv1_test = x0 .NEQV. x1
+END FUNCTION
+
+! CHECK-LABEL:or2_test
+LOGICAL(1) FUNCTION or2_test(x0, x1)
+LOGICAL(1) :: x0
+LOGICAL(1) :: x1
+! CHECK-DAG:[[reg1:%[0-9]+]] = fir.load %arg0
+! CHECK-DAG:[[reg2:%[0-9]+]] = fir.load %arg1
+! CHECK-DAG:[[reg3:%[0-9]+]] = fir.convert [[reg1]] {{.*}} -> i1
+! CHECK-DAG:[[reg4:%[0-9]+]] = fir.convert [[reg2]] {{.*}} -> i1
+! CHECK:[[reg5:%[0-9]+]] = arith.ori [[reg3]], [[reg4]]
+! CHECK:fir.convert [[reg5]] {{.*}} -> !fir.logical<1>
+or2_test = x0 .OR. x1
+END FUNCTION
+
+! CHECK-LABEL:and3_test
+LOGICAL(1) FUNCTION and3_test(x0, x1)
+LOGICAL(1) :: x0
+LOGICAL(1) :: x1
+! CHECK-DAG:[[reg1:%[0-9]+]] = fir.load %arg0
+! CHECK-DAG:[[reg2:%[0-9]+]] = fir.load %arg1
+! CHECK-DAG:[[reg3:%[0-9]+]] = fir.convert [[reg1]] {{.*}} -> i1
+! CHECK-DAG:[[reg4:%[0-9]+]] = fir.convert [[reg2]] {{.*}} -> i1
+! CHECK:[[reg5:%[0-9]+]] = arith.andi [[reg3]], [[reg4]]
+! CHECK:fir.convert [[reg5]] {{.*}} -> !fir.logical<1>
+and3_test = x0 .AND. x1
+END FUNCTION
+
+! CHECK-LABEL:not4_test
+LOGICAL(1) FUNCTION not4_test(x0)
+LOGICAL(1) :: x0
+! CHECK:[[reg1:%[0-9]+]] = fir.load %arg0
+! CHECK:[[reg2:%[0-9]+]] = fir.convert [[reg1]] {{.*}} -> i1
+! CHECK:[[reg3:%[0-9]+]] = arith.xori [[reg2]], %true
+! CHECK:fir.convert [[reg3]] {{.*}} -> !fir.logical<1>
+not4_test = .NOT. x0
+END FUNCTION