Non-steroidal anti-inflammatory drugs (NSAIDs) are used widely to relieve pain, with or without inflammation, in people with both acute and chronic musculoskeletal disorders. Over 20 NSAIDs, available in at least 40 different formulations, are listed in the British National Formulary. The efficacy of specific NSAIDs is hard to predict in individual patients, unwanted effects are common and some are serious. In this article we offer guidelines for the rational and safe use of NSAIDs for musculoskeletal disorders in adults.