Although the increased need for studies assessing the influence of age on the pharmacokinetics and pharmacodynamics of all drugs has been emphasized, relatively little is known about NSAIDs in the elderly. The pharmacokinetics of some NSAIDs have been examined in elderly subjects; unfortunately, recent data indicate that much of the earlier information may be incomplete or even misleading. Many studies report the disposition of only total NSAIDs. Since all of the NSAIDs are highly protein bound, it is the unbound, pharmacologically active, fraction that is most important. Few studies have quantified the pharmacokinetics of unbound NSAID in any age group, much less in elderly patients. Also, it is now apparent that studies of the propionic acid derivatives and other drugs with chiral centers must assess the disposition of the active S-enantiomer. Finally, studies of NSAIDs that form acylglucuronides are confounded by the reversion of these metabolites to active drug. Reduced renal elimination of these metabolites may be greater in elderly persons. Studies that account for these features of NSAIDs will provide necessary data for safe and effective use of NSAIDs in the elderly.