We reviewed 526 medical records of surgical patients and interviewed 81 of these patients. We also sent questionnaires to house staff (57 of 97 responded) and nurses (70 of 142 responded) involved in the care of these patients. A substantial number of patients suffered at least moderate pain during the postoperative period despite analgesic medication. Patients received 70% of the maximal ordered analgesic dose in the first 24 hours. Physicians prescribed drugs in doses that were often inadequate and to be given at inflexible intervals. The optimal doses and duration of action of meperidine, as judged by the house staff and nurses, did not agree with the accepted pharmacologic profile of this drug.