A randomized study on 30 patients undergoing knee arthroscopy was performed. Group I (n = 15) received 50 mg of 0.25% bupivacaine and 1 mg of morphine, and group II (n = 15) received 50 mg of 0.25% bupivacaine and 100 micrograms of fentanyl. The visual analogue scale was recorded at intervals of 1, 2, 3, 4, 6, 12, 24, and 48 hours after the operation. Supplementary analgesia requirements were also recorded. In group I, pain scores were lower than group II (P < .05) during the 1st, 2nd, 3rd, 12th, 24th, and 48th hours. The duration of analgesia on group I was significantly longer than group II. The combination of intraarticular morphine and bupivacaine has a longer analgesic duration and effect than a combination of fentanyl and bupivacaine.