diff --git a/dcrdtest/rpc_harness.go b/dcrdtest/rpc_harness.go
index 36f0401..6194df0 100644
--- a/dcrdtest/rpc_harness.go
+++ b/dcrdtest/rpc_harness.go
@@ -67,6 +67,8 @@ type Harness struct {
 	maxConnRetries int
 	nodeNum        int
 
+	keepNodeDir bool
+
 	sync.Mutex
 }
 
@@ -214,6 +216,15 @@ func New(t *testing.T, activeNet *chaincfg.Params, handlers *rpcclient.Notificat
 	return h, nil
 }
 
+// SetKeepNodeDir sets the flag  in the Harness on whether to keep or remove
+// its node dir after TearDown is called.
+//
+// This is NOT safe for concurrent access and MUST be called from the same
+// goroutine that calls SetUp and TearDown.
+func (h *Harness) SetKeepNodeDir(keep bool) {
+	h.keepNodeDir = keep
+}
+
 // SetUp initializes the rpc test state. Initialization includes: starting up a
 // simnet node, creating a websockets client and connecting to the started
 // node, and finally: optionally generating and submitting a testchain with a
@@ -319,13 +330,28 @@ func (h *Harness) TearDown() error {
 		h.wallet = nil
 	}
 
+	if !h.keepNodeDir {
+		if err := os.RemoveAll(h.testNodeDir); err != nil {
+			log.Warnf("Unable to remove test node dir %s: %v", h.testNodeDir, err)
+		} else {
+			log.Debugf("Removed test node dir %s", h.testNodeDir)
+		}
+	}
+
 	return nil
 }
 
 // TearDownInTest performs the TearDown during a test, logging the error to the
 // test object. If the test has not yet failed and the TearDown itself fails,
 // then this fails the test.
+//
+// If the test has already failed, then the dir for node data is kept for manual
+// debugging.
 func (h *Harness) TearDownInTest(t testing.TB) {
+	if t.Failed() {
+		h.SetKeepNodeDir(true)
+	}
+
 	err := h.TearDown()
 	if err != nil {
 		errMsg := fmt.Sprintf("Unable to teardown dcrdtest harness: %v", err)
diff --git a/dcrdtest/rpc_harness_test.go b/dcrdtest/rpc_harness_test.go
index b29b5cc..687c176 100644
--- a/dcrdtest/rpc_harness_test.go
+++ b/dcrdtest/rpc_harness_test.go
@@ -703,6 +703,12 @@ func TestSetupTeardown(t *testing.T) {
 		t.Fatalf("Unexpected nb of active goroutines: got %d, want %d",
 			gotCount, wantCount)
 	}
+
+	// Node dir should've been removed.
+	if _, err := os.Stat(mainHarness.testNodeDir); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("Unexpected Stat(testNodeDir) error: got %v, want %v",
+			err, os.ErrNotExist)
+	}
 }
 
 // TestSetupWithError tests that when the setup of an rpc harness fails, it
@@ -794,3 +800,37 @@ func TestSetupWithWrongDcrd(t *testing.T) {
 		t.Fatalf("Unexpected error during TearDown: %v", err)
 	}
 }
+
+// TestKeepNodeDir asserts that when the harness is set to keep the node dir,
+// it is not removed after TearDown().
+func TestKeepNodeDir(t *testing.T) {
+	// Add logging to ease debugging this test.
+	lw := loggerWriter{l: t}
+	bknd := slog.NewBackend(lw)
+	UseLogger(bknd.Logger("TEST"))
+	log.SetLevel(slog.LevelDebug)
+	defer UseLogger(slog.Disabled)
+
+	params := chaincfg.RegNetParams()
+	mainHarness, err := New(t, params, nil, nil)
+	if err != nil {
+		t.Fatalf("unable to create main harness: %v", err)
+	}
+
+	// Perform the setup. This should succeed.
+	ctx := testctx.WithTimeout(t, time.Second*30)
+	if err := mainHarness.SetUp(ctx, true, 2); err != nil {
+		t.Fatalf("Unexpected error in Setup(): got %v, want %v", err, nil)
+	}
+
+	// Set to keep the node dir.
+	mainHarness.SetKeepNodeDir(true)
+
+	// Perform the TearDown. This should not error and the node dir should
+	// be kept.
+	mainHarness.TearDownInTest(t)
+	if _, err := os.Stat(mainHarness.testNodeDir); err != nil {
+		t.Fatalf("Unexpected Stat(testNodeDir) error: got %v, want %v",
+			err, nil)
+	}
+}