Portable, lightweight manually actuated CPR device for performing enhanced external thoracic massage. When applied to the victim, the device is used to perform chest, or chest and abdominal compression cardiopulmonary resuscitation (CPR). The device provides mechanical force advantage over manually-performed external thoracic massage and permits performing multiple, repeatable and controlled compression/decompression cycles in rapid succession. The system requires less physical strength and endurance than the traditional external thoracic massage, and can be used by persons who otherwise are not strong enough to perform effective CPR. The device can be used with external ECG and defibrillation electrodes and equipment, is lightweight and portable, and can be used by both professional and lay rescuers.