A clinical study examining the efficacy of Patient Controlled Analgesia compared with Intramuscular Analgesia was conducted. Patient Controlled Analgesia (PCA) Therapy was used in a select group of patients after major abdominal surgery. Specific parameters monitored were: total amount of analgesia required, incidence of pulmonary complications, assessment of pain level and sedation, patient activity, nursing time required for administration, safety, cost-effectiveness of both modes of analgesia and length of hospital stay. A questionnaire survey of both patients and nursing staff was done to evaluate responses. Conventional pain management often is inadequate with PRN administration of analgesic drugs due to the unpredictable and uneven patient absorption rate and the individual pain intensity and tolerance. The patient experiences a repetitive cycle of pain and sedation. The patient on PCA therapy is able to titrate his analgesic medication very effectively and maintain a state of analgesia without sedation. He is more responsive and able to participate in the early postoperative rehabilitation phase. The transition to oral medication usually was accomplished at 48 hours postoperative.