Celecoxib is a non-steroidal anti-inflammatory drug (NSAID) which acts via specific inhibition of cyclooxygenase-2 (synthesis of prostaglandins mediating pathological inflammation) but which preserves the homeostatic action of cyclooxygenase-1. The efficacy of celecoxib is similar to that of classical NSAIDs and its tolerance is comparable with that of placebo. We nevertheless observed one patient with hypersensitivity to celecoxib who developed fever, toxic skin reaction, and liver involvement.