With its FDA approval in November, valdecoxib becomes the hird COX-2 inhibitor to gain US market clearance. This Focus article examines valdecoxib's pharmacologic, pharmacokinetic, and therapeutic aspects and considers its role in relation to other COX-2 inhibitors and traditional NSAIDs. Special attention is devoted to its comparative COX-1:COX-2 inhibitory ratio and an array of unpublished efficacy and safety trials.