Opioid agents are highly effective analgesics after orthopedic surgery but are associated with several adverse effects. Valdecoxib is a new, highly selective cyclooxygenase (COX)-2-specific inhibitor with a rapid onset of action and significant analgesic properties that is being developed for the management of acute pain. The objective of this study was to demonstrate the opioid-sparing efficacy of valdecoxib as part of a multimodal treatment of pain associated with hip arthroplasty. This multicenter, multiple-dose, double-blind, parallel-group study compared the opioid-sparing effects, analgesic efficacy, and safety of 20- and 40-mg doses of valdecoxib twice daily with placebo in patients receiving morphine by patient-controlled analgesia after hip arthroplasty. Study medication was first administered 1 to 3 hours preoperatively. The total amount of morphine administered, pain intensity, and patient's global evaluation of study medication were assessed over a period of 48 hours. Patients receiving 20 or 40 mg valdecoxib twice daily required on average 40% less morphine than those receiving placebo after hip arthroplasty. Pain intensity levels and patient satisfaction were significantly improved in both valdecoxib groups compared with placebo. Valdecoxib and placebo were equally well tolerated. Pre- and postoperative administration of valdecoxib reduces the amount of morphine required for postoperative pain relief and provides greater analgesic efficacy compared with morphine alone. Thus, valdecoxib has significant clinical utility for acute pain management in orthopedic surgery patients.