diff --git a/pkg/models/project.go b/pkg/models/project.go
index 035a2c73b33..509b7f567ec 100644
--- a/pkg/models/project.go
+++ b/pkg/models/project.go
@@ -1041,10 +1041,28 @@ func (p *Project) Delete(s *xorm.Session, a web.Auth) (err error) {
 		return
 	}
 
-	return events.Dispatch(&ProjectDeletedEvent{
+	err = events.Dispatch(&ProjectDeletedEvent{
 		Project: fullProject,
 		Doer:    a,
 	})
+	if err != nil {
+		return
+	}
+
+	childProjects := []*Project{}
+	err = s.Where("parent_project_id = ?", fullProject.ID).Find(&childProjects)
+	if err != nil {
+		return
+	}
+
+	for _, child := range childProjects {
+		err = child.Delete(s, a)
+		if err != nil {
+			return
+		}
+	}
+
+	return
 }
 
 // DeleteBackgroundFileIfExists deletes the list's background file from the db and the filesystem,
diff --git a/pkg/models/user_delete.go b/pkg/models/user_delete.go
index 8548daff545..ab6ef7cc6fe 100644
--- a/pkg/models/user_delete.go
+++ b/pkg/models/user_delete.go
@@ -137,6 +137,10 @@ func DeleteUser(s *xorm.Session, u *user.User) (err error) {
 	}
 
 	for _, p := range projectsToDelete {
+		if p.ParentProjectID != 0 {
+			// Child projects are deleted by p.Delete
+			continue
+		}
 		err = p.Delete(s, u)
 		// If the user is the owner of the default project it will be deleted, if they are not the owner
 		// we can ignore the error as the project was shared in that case.