The elderly often suffer from chronic musculoskeletal disease, and non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to control symptoms. The aged have been shown to be particularly at risk of adverse effects from these drugs, of which gastrointestinal irritation and bleeding are both common and potentially serious. Because of this, a comparison of NSAID pharmacokinetics in young and elderly subjects is of particular importance. In general, protein binding tends to decrease with age; volumes of distribution may undergo a small increase; and clearance, especially of renally eliminated drugs, may fall. However, these changes are relatively minor, and the increased propensity of the elderly to suffer adverse reactions to NSAIDs cannot readily be explained on a pharmacokinetic basis.