diff --git a/charts/kargo/templates/webhooks/webhooks.yaml b/charts/kargo/templates/webhooks/webhooks.yaml
index 47200022a4..2dec7d37f8 100644
--- a/charts/kargo/templates/webhooks/webhooks.yaml
+++ b/charts/kargo/templates/webhooks/webhooks.yaml
@@ -39,6 +39,21 @@ webhooks:
     resources: ["promotions"]
     operations: ["CREATE", "UPDATE"]
   failurePolicy: Fail
+- name: promotiontask.kargo.akuity.io
+  admissionReviewVersions: [ "v1" ]
+  sideEffects: None
+  clientConfig:
+    service:
+      namespace: {{ .Release.Namespace }}
+      name: kargo-webhooks-server
+      path: /validate-kargo-akuity-io-v1alpha1-promotiontask
+  rules:
+    - scope: Namespaced
+      apiGroups: ["kargo.akuity.io"]
+      apiVersions: ["v1alpha1"]
+      resources: ["promotiontasks"]
+      operations: ["CREATE"]
+  failurePolicy: Fail
 - name: stage.kargo.akuity.io
   admissionReviewVersions: ["v1"]
   sideEffects: None
diff --git a/cmd/controlplane/webhooks.go b/cmd/controlplane/webhooks.go
index 2d50bffe9c..0d67806511 100644
--- a/cmd/controlplane/webhooks.go
+++ b/cmd/controlplane/webhooks.go
@@ -24,6 +24,7 @@ import (
 	"github.com/akuity/kargo/internal/webhook/freight"
 	"github.com/akuity/kargo/internal/webhook/project"
 	"github.com/akuity/kargo/internal/webhook/promotion"
+	"github.com/akuity/kargo/internal/webhook/promotiontask"
 	"github.com/akuity/kargo/internal/webhook/stage"
 	"github.com/akuity/kargo/internal/webhook/warehouse"
 )
@@ -135,6 +136,9 @@ func (o *webhooksServerOptions) run(ctx context.Context) error {
 	if err = promotion.SetupWebhookWithManager(ctx, webhookCfg, mgr); err != nil {
 		return fmt.Errorf("setup Promotion webhook: %w", err)
 	}
+	if err = promotiontask.SetupWebhookWithManager(mgr); err != nil {
+		return fmt.Errorf("setup PromotionTask webhook: %w", err)
+	}
 	if err = stage.SetupWebhookWithManager(webhookCfg, mgr); err != nil {
 		return fmt.Errorf("setup Stage webhook: %w", err)
 	}
diff --git a/internal/webhook/promotiontask/webhook.go b/internal/webhook/promotiontask/webhook.go
new file mode 100644
index 0000000000..3b91a22e57
--- /dev/null
+++ b/internal/webhook/promotiontask/webhook.go
@@ -0,0 +1,51 @@
+package promotiontask
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+
+	kargoapi "github.com/akuity/kargo/api/v1alpha1"
+	libWebhook "github.com/akuity/kargo/internal/webhook"
+)
+
+var promotionTaskGroupKind = schema.GroupKind{
+	Group: kargoapi.GroupVersion.Group,
+	Kind:  "PromotionTask",
+}
+
+type webhook struct {
+	client client.Client
+}
+
+func SetupWebhookWithManager(
+	mgr ctrl.Manager,
+) error {
+	w := &webhook{
+		client: mgr.GetClient(),
+	}
+	return ctrl.NewWebhookManagedBy(mgr).
+		For(&kargoapi.PromotionTask{}).
+		WithValidator(w).
+		Complete()
+}
+
+func (w *webhook) ValidateCreate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
+	template := obj.(*kargoapi.PromotionTask) // nolint: forcetypeassert
+	if err := libWebhook.ValidateProject(ctx, w.client, promotionTaskGroupKind, template); err != nil {
+		return nil, err
+	}
+	return nil, nil
+}
+
+func (w *webhook) ValidateUpdate(context.Context, runtime.Object, runtime.Object) (admission.Warnings, error) {
+	return nil, nil
+}
+
+func (w *webhook) ValidateDelete(context.Context, runtime.Object) (admission.Warnings, error) {
+	return nil, nil
+}
diff --git a/internal/webhook/promotiontask/webhook_test.go b/internal/webhook/promotiontask/webhook_test.go
new file mode 100644
index 0000000000..4c3cf10465
--- /dev/null
+++ b/internal/webhook/promotiontask/webhook_test.go
@@ -0,0 +1,94 @@
+package promotiontask
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+
+	kargoapi "github.com/akuity/kargo/api/v1alpha1"
+)
+
+func Test_webhook_ValidateCreate(t *testing.T) {
+	scheme := runtime.NewScheme()
+	require.NoError(t, corev1.AddToScheme(scheme))
+	require.NoError(t, kargoapi.AddToScheme(scheme))
+
+	tests := []struct {
+		name       string
+		objects    []client.Object
+		template   *kargoapi.PromotionTask
+		assertions func(*testing.T, admission.Warnings, error)
+	}{
+		{
+			name: "project does not exist",
+			objects: []client.Object{
+				&corev1.Namespace{
+					ObjectMeta: v1.ObjectMeta{
+						Name: "fake-project",
+					},
+				},
+			},
+			template: &kargoapi.PromotionTask{
+				ObjectMeta: v1.ObjectMeta{
+					Name:      "fake-template",
+					Namespace: "fake-project",
+				},
+			},
+			assertions: func(t *testing.T, warnings admission.Warnings, err error) {
+				assert.Empty(t, warnings)
+				assert.ErrorContains(t, err, "namespace \"fake-project\" is not a project")
+			},
+		},
+		{
+			name: "project exists",
+			objects: []client.Object{
+				&corev1.Namespace{
+					ObjectMeta: v1.ObjectMeta{
+						Name: "fake-project",
+						Labels: map[string]string{
+							kargoapi.ProjectLabelKey: kargoapi.LabelTrueValue,
+						},
+					},
+				},
+				&kargoapi.Project{
+					ObjectMeta: v1.ObjectMeta{
+						Name: "fake-project",
+					},
+				},
+			},
+			template: &kargoapi.PromotionTask{
+				ObjectMeta: v1.ObjectMeta{
+					Name:      "fake-template",
+					Namespace: "fake-project",
+				},
+			},
+			assertions: func(t *testing.T, warnings admission.Warnings, err error) {
+				assert.Empty(t, warnings)
+				assert.NoError(t, err)
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := fake.NewClientBuilder().
+				WithObjects(tt.objects...).
+				WithScheme(scheme).
+				Build()
+
+			w := &webhook{
+				client: c,
+			}
+
+			got, err := w.ValidateCreate(context.Background(), tt.template)
+			tt.assertions(t, got, err)
+		})
+	}
+}