Laparoscopic cholecystectomy is associated with a high incidence of postoperative pain, nausea, and vomiting. Pneumoperitoneum created during the operation and residual gas after the operation are two of the factors in postoperative pain and nausea. We studied the effects of a subdiaphragmatic gas drain, which is intended to decrease the residual gas, on postoperative pain, nausea, and vomiting after laparoscopic cholecystectomy. Seventy patients were randomized into two demographically and clinically comparable groups: drainage and control. Postoperative pain, nausea, and vomiting were measured by verbal grading and visual analog scale 2-72 h postoperatively. Analgesic and antiemetic use and incidence of retching, vomiting and other complaints were also recorded. Subdiaphragmatic drain effectively reduced the incidence and amount of subdiaphragmatic gas bubble. The incidence and severity of nausea was lower in the drainage group at 72 h. Although severity of pain was lower at 8 and 12 h in the drainage group, the difference was not significant. There was also no difference between the groups in regard to analgesic and antiemetic use. Subdiaphragmatic drain offers only minor, if any, benefit on postoperative pain, nausea, and vomiting after laparoscopic cholecystectomy, and this effect is probably clinically irrelevant.