diff --git a/app/main/forms.py b/app/main/forms.py
index 6b8a224a2..eb82e9be6 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -238,4 +238,14 @@ class ConfirmMobileNumberForm(Form):
 
 
 class CreateKeyForm(Form):
-    key_name = StringField(u'Description of key')
+    def __init__(self, existing_key_names=[], *args, **kwargs):
+        self.existing_key_names = existing_key_names
+        super(CreateKeyForm, self).__init__(*args, **kwargs)
+
+    key_name = StringField(u'Description of key', validators=[
+        DataRequired(message='You need to give the key a name')
+    ])
+
+    def validate_key_name(self, key_name):
+        if key_name.data in self.existing_key_names:
+            raise ValidationError('A key with this name already exists')
diff --git a/app/main/views/api_keys.py b/app/main/views/api_keys.py
index f3790d174..e2d77bf31 100644
--- a/app/main/views/api_keys.py
+++ b/app/main/views/api_keys.py
@@ -24,7 +24,10 @@ def api_keys(service_id):
 @main.route("/services/<int:service_id>/api-keys/create", methods=['GET', 'POST'])
 @login_required
 def create_api_key(service_id):
-    form = CreateKeyForm()
+    key_names = [
+        key['name'] for key in api_key_api_client.get_api_keys(service_id=service_id)['apiKeys']
+    ]
+    form = CreateKeyForm(key_names)
     if form.validate_on_submit():
         secret = api_key_api_client.create_api_key(service_id=service_id, key_name=form.key_name.data)
         return render_template('views/api-keys/show.html', service_id=service_id, secret=secret,
diff --git a/tests/app/main/test_create_api_key_form.py b/tests/app/main/test_create_api_key_form.py
new file mode 100644
index 000000000..54608da6f
--- /dev/null
+++ b/tests/app/main/test_create_api_key_form.py
@@ -0,0 +1,16 @@
+from werkzeug.datastructures import MultiDict
+
+from app.main.forms import CreateKeyForm
+
+
+def test_return_validation_error_when_key_name_exists(app_,
+                                                      db_,
+                                                      db_session):
+    def _get_names():
+        return ['some key', 'another key']
+
+    with app_.test_request_context():
+        form = CreateKeyForm(_get_names(),
+                             formdata=MultiDict([('key_name', 'some key')]))
+        form.validate()
+        assert {'key_name': ['A key with this name already exists']} == form.errors
diff --git a/tests/app/main/views/test_api_keys.py b/tests/app/main/views/test_api_keys.py
index fbd2054ea..e1b114398 100644
--- a/tests/app/main/views/test_api_keys.py
+++ b/tests/app/main/views/test_api_keys.py
@@ -62,7 +62,8 @@ def test_should_show_name_api_key_page(app_,
                                        active_user,
                                        mock_get_service,
                                        mock_get_services,
-                                       mock_user_loader):
+                                       mock_user_loader,
+                                       mock_get_api_keys):
     with app_.test_request_context():
         with app_.test_client() as client:
             client.login(active_user)
@@ -78,7 +79,8 @@ def test_should_render_show_api_key(app_,
                                     mock_get_service,
                                     mock_get_services,
                                     mock_user_loader,
-                                    mock_create_api_key):
+                                    mock_create_api_key,
+                                    mock_get_api_keys):
     with app_.test_request_context():
         with app_.test_client() as client:
             client.login(active_user)