Side effects of nonsteroidal anti-inflammatory drugs (NSAIDs) most commonly affect the gastrointestinal tract and the kidney. The recent release of selective cyclooxygenase-2 (COX-2) inhibitors has been associated with a decrease in adverse gastrointestinal effects. However, the nephrotoxic potential of these drugs still remains controversial. Here, we report the case of a previously healthy woman with reversible acute renal failure associated with eight days of anuria following the administration of valdecoxib, a newly released selective cyclooxygenase-2 inhibitor, during an episode of acute febrile pyelonephritis. We suggest that selective COX-2 inhibitors should not be used in patients with volume contraction and underlying renal disease.