Background-Ketoprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events. Objectives-To assess efficacy, duration of action, and associated adverse events of single dose oral ketoprofen and dexketoprofen in acute postoperative pain in adults. Search methods-We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to August 2009. Selection criteria-Randomised, double blind, placebo-controlled trials of single dose orally administered ketoprofen and dexketoprofen in adults with moderate to severe acute postoperative pain. Data collection and analysis-Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which