Ketoprofen (Orudis) is a nonsteroidal anti-inflammatory drug that is currently approved in the United States for the management of mild to moderate pain. The objective of this trial was to determine the effectiveness of orally administered ketoprofen in the management of severe postoperative pain. This randomized, double-blind parallel study compared the efficacy and safety of single doses of 100 mg or 50 mg ketoprofen, the combination of 650 mg acetaminophen plus 10 mg oxycodone hydrochloride, 650 mg acetaminophen, or placebo in 240 patients with severe postoperative pain after cesarean section. Analgesia for the first dose was assessed over an 8-hour period. Multiple doses of 100 mg or 50 mg ketoprofen and the combination at half the dose (325 mg acetaminophen plus 5 mg oxycodone) were also assessed for up to 7 days. The 100 and 50 mg doses of ketoprofen and the combination were statistically superior to acetaminophen and placebo for many analgesic measures. A dose response was observed between the two doses of ketoprofen, with the 100 mg dose providing significantly greater analgesia over the lower dose. Ketoprofen, 100 mg, was at least as effective as the combination and its effects lasted longer, with the exception of hour 1 when the combination was superior. Remedication time for the group receiving 100 mg ketoprofen was significantly longer than for the other treatment groups. Significantly more patients who took repeated doses of the combination (84%) than those who took either dose of ketoprofen (70%) had adverse effects. Ketoprofen at both dose levels was shown to be effective, long-lasting, and well tolerated, and it should be considered as a viable option for the management of moderate to severe postoperative pain.