To investigate the effects of electromyography (EMG)-biofeedback on pain experienced during the immediate post-operative period following abdominal surgery, twelve patients were randomly assigned to either (1) EMG-biofeedback from abdominal muscles; (2) EMG-biofeedback from the frontalis muscles; or (3) were given no EMG treatment. EMG training consisted on one pre-operative 30 minute session, and three 30 minute postoperative sessions. All patients were able to reduce EMG activity. A within-sessions analysis of pain reports (on a 0-10 pain intensity scale) indicated that EMG biofeedback is an effective method of pain relief only when feedback is given to the muscle site involved in the operation.