This study compared the analgesic effect of intra-articular injection of tenoxicam with that of morphine on postoperative pain after anterior cruciate ligament (ACL) reconstruction. Forty-two patients undergoing arthroscopically ACL reconstructions using hamstring tendons underwent the same anesthetic protocol. The patients were randomized to receive 25 ml normal saline, 20 mg tenoxicam in 25 ml normal saline, or 2 mg morphine in 25 ml normal saline. Postoperative pain was assessed using a visual analogue scale and measuring analgesic requirements. We found both that both intra-articular tenoxicam and intra-articular morphine provided better analgesia than that in the control group. Although pain scores were similar between tenoxicam and morphine groups 30 min postoperative, the analgesic requirements in with tenoxicam were significantly lower than those with morphine group 3-6 h postoperatively.