Background The aim of this study was to compare the effects of nalbuphine and sufentanil on the gastrointestinal (GI) tract after laparoscopic surgery for gynecological malignancies. Methods A total of 100 patients aged between 18-70 years with American Society of Anesthesiologists (ASA) physical status I-II who scheduled for laparoscopic radical hysterectomy under general anaesthesia were enrolled. Patients were randomized to receive either sufentanil (Group S) or nalbuphine (Group N) to receive either sufentanil (Group S) or nalbuphine (Group N) in the intraoperative and postoperative periods. The time to the first passage of flatus, the time to the first defecation, the time to the toleration of diet, the serum gastrin and the length of hospital stay were compared between the groups. Postoperative pain by visual analogue scale (VAS), the number of PCA(patient-controlled analgesia)s, postoperative nausea and vomiting, and dizziness were compared between the groups. Results The time to the first passage of flatus(p =0.551), the time to the first defecation(p =0.310), the time to the toleration of diet(p =0.182), the serum gastrin(p =0.397), the number of postoperative nausea(p =0.920), vomit(p =0.334) and PCA events(p =0.167) and the length of hospital stay(p =0.482) were not significantly different between the two groups. VAS scores at postoperative 6 h(p=0.008), 12 h(p =0.002) and 24 h(p =0.013) were lower in Group N than in Group S. Conclusions Compared with sufentanil, nalbuphine was not associated with improved postoperative GI dysfunction after laparoscopic surgery for gynecological malignancies, but it was associated with reduced postoperative pain. Background Postoperative gastrointestinal (GI) dysfunction such as nausea, vomiting, inability to eat, deflation, prolonged bowel movements, and paralytic ileus are some of the most common complications after surgery, and the incidence is nearly 10-30%(1). The occurrence of postoperative GI dysfunction leads