diff --git a/client/src/app/site/motions/modules/category/components/category-detail/category-detail.component.ts b/client/src/app/site/motions/modules/category/components/category-detail/category-detail.component.ts
index 01c444cd9..288aee6bf 100644
--- a/client/src/app/site/motions/modules/category/components/category-detail/category-detail.component.ts
+++ b/client/src/app/site/motions/modules/category/components/category-detail/category-detail.component.ts
@@ -158,7 +158,7 @@ export class CategoryDetailComponent extends BaseViewComponent implements OnInit
      * Click handler to delete a category
      */
     public async onDeleteButton(): Promise<void> {
-        const title = this.translate.instant('Are you sure you want to delete this category?');
+        const title = this.translate.instant('Are you sure you want to delete this category and all subcategories?');
         const content = this.selectedCategory.prefixedName;
         if (await this.promptService.open(title, content)) {
             await this.repo.delete(this.selectedCategory);
diff --git a/client/src/app/site/motions/modules/category/components/category-list/category-list.component.ts b/client/src/app/site/motions/modules/category/components/category-list/category-list.component.ts
index defe562a1..18f8afa46 100644
--- a/client/src/app/site/motions/modules/category/components/category-list/category-list.component.ts
+++ b/client/src/app/site/motions/modules/category/components/category-list/category-list.component.ts
@@ -80,7 +80,7 @@ export class CategoryListComponent extends BaseViewComponent implements OnInit {
 
         this.dataSource = new MatTableDataSource();
         this.repo.getViewModelListObservable().subscribe(viewCategories => {
-            if (viewCategories && viewCategories.length && this.dataSource) {
+            if (viewCategories && this.dataSource) {
                 this.dataSource.data = viewCategories;
             }
         });
diff --git a/openslides/motions/migrations/0032_category_cascade_delete.py b/openslides/motions/migrations/0032_category_cascade_delete.py
new file mode 100644
index 000000000..845cb75bc
--- /dev/null
+++ b/openslides/motions/migrations/0032_category_cascade_delete.py
@@ -0,0 +1,24 @@
+# Generated by Django 2.2.3 on 2019-08-05 10:50
+
+from django.db import migrations, models
+
+import openslides.utils.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [("motions", "0031_state_css_classes_2")]
+
+    operations = [
+        migrations.AlterField(
+            model_name="category",
+            name="parent",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=openslides.utils.models.CASCADE_AND_AUTOUPDATE,
+                related_name="children",
+                to="motions.Category",
+            ),
+        )
+    ]
diff --git a/openslides/motions/models.py b/openslides/motions/models.py
index 9c181afe5..d5e6ba9a8 100644
--- a/openslides/motions/models.py
+++ b/openslides/motions/models.py
@@ -804,14 +804,14 @@ class Category(RESTModelMixin, models.Model):
     """Name of the category."""
 
     prefix = models.CharField(blank=True, max_length=32)
-    """Prefix of the category.
-
+    """
+    Prefix of the category.
     Used to build the identifier of a motion.
     """
 
     parent = models.ForeignKey(
         "self",
-        on_delete=SET_NULL_AND_AUTOUPDATE,
+        on_delete=CASCADE_AND_AUTOUPDATE,
         null=True,
         blank=True,
         related_name="children",