The traditional intramuscular injection of opioids does not provide adequate pain relief for patients who have undergone major surgery. An acute pain service that provides patient-controlled analgesia and epidural analgesia can not only provide superior analgesia but may improve surgical outcome. However, a review of the current literature does not clearly define the relationship between the quality of analgesia and post-operative outcome. This is due to limitations in study design and methodology. On the other hand, several studies quite convincingly demonstrate a beneficial effect on high risk patients undergoing major surgery. Further studies would be necessary to define the full extent of potential benefits and optimal techniques. the integration of an acute pain service with surgical and nursing care may give patients the best outcome.