BACKGROUND Nabumetone is a non-steroidal anti-inflammatory drug (NSAID) used mainly in treating pain associated with arthritis. The usual oral dose for osteoarthritis is 1000 mg daily, and higher doses are not advised in older patients. There are no known systematic reviews of its analgesic efficacy in acute postoperative pain. This review sought to evaluate the efficacy and safety of oral nabumetone in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish whether drugs have analgesic properties. OBJECTIVE To assess the efficacy of single dose oral nabumetone in acute postoperative pain, and any associated adverse events. METHODS We searched The Cochrane Library (Issue 2, 2009), MEDLINE (May 2009); EMBASE via Ovid (May 2009); and the Oxford Pain Relief Database. METHODS Randomised, double-blind, placebo-controlled clinical trials of oral nabumetone for relief of acute postoperative pain in adults. METHODS Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with nabumetone and placebo experiencing at least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected. RESULTS No studies were identified by the searches that examined oral nabumetone in participants with established postoperative pain. CONCLUSIONS In the absence of evidence of efficacy, at present, for oral nabumetone in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.