BACKGROUND Postoperative pain is a major problem following laparoscopic cholecystectomy, and there is no general agreement on the effective method of pain relief. Rectal morphine suppositories are one of the newly released morphine forms. The aim of this study is to compare the impact of suppository morphine with placebo on pain relief after laparoscopic cholecystectomy. METHODS Seventy patients scheduled for elective laparoscopic cholecystectomy under general anesthesia, were randomly allocated to two groups according to the drug used for postoperative analgesia: Group morphine suppository (MS - 10 mg) just before induction of anesthesia And Group placebo suppository (PS) (the pills were made from cocoa butter, physically similar to the real drug). Pain intensity based on visual analog scale (VAS) and opioid consumption were assessed 30 and 60 min, and 2, 4, 8, 16, and 24 h after arrival of the patient to the recovery room. RESULTS VAS scores were significantly lower in MS group (from 3.8 ± 1 to 5.3 ± 1.6) compared with PS group (from 4.9 ± 0.9 to 6.7 ± 1) from 30 min after arrival to the recovery room until 16 h postoperatively (P < 0.05). There were no additional analgesic requirements in the first 2 h after the entrance of the patient to the recovery room in MS group. The number of patients requiring pethidine was significantly different between two groups (P < 0.05) in all periods except for 24 h postoperatively. CONCLUSIONS Suppository morphine administration is more effective than placebo to reduce pain and analgesic requirements after laparoscopic cholecystectomy.