['To assess the safety and efficacy of ondansetron for prevention of pruritus, nausea and vomiting after cesarean delivery with intrathecal sufentanil-morphine.', 'Randomized, double-blind, placebo-controlled study.', 'Referral center, institutional practice.', '100 nonbreastfeeding women undergoing elective cesarean delivery with sufentanil-morphine-bupivacaine anesthesia.', 'After the umbilical cord was clamped, patients in Group 1 received ondansetron 8 mg intravenously (IV) and patients in Group 2 received placebo.', 'Frequency and severity of postoperative (24-hour) pruritus, nausea and vomiting, surgical pain, and side effects related to ondansetron were recorded.', 'In the ondansetron group, 38 patients had pruritus (16 mild and 22 severe) and 9 patients had nausea and vomiting (5 mild and 4 severe). In the placebo group, 41 patients had pruritus (21 mild and 20 severe) and 29 patients had nausea and vomiting (9 mild and 15 severe). The frequency and severity of the nausea and vomiting episodes were significantly reduced in the ondansetron group. Pain scores were comparable between groups. No side effects related to ondansetron were reported.'] Is prophylactic ondansetron effective in the treatment of nausea and vomiting but not on pruritus after cesarean delivery with intrathecal sufentanil-morphine?