Abstract: A restraining device for preventing undesireable motion of a manually propelled cart, or a shopping cart brake, in accordance with the present invention generally includes a frame, a brake foot mounted thereto, and a counterweight for balancing the brake foot in a disengaged position. The device is preferably mounted to a front crossbar of a conventional shopping cart, and upon a manual jerking motion of the cart, the brake foot swings into engagement with a ground surface thus lifting the front wheels off the ground and immobilizing the cart. No levers or complex mechanics are required to engage the brake. The device may also include a hinged door for insertion of product promotions or advertisements on a highly visible portion of the device frame.