Summary What is known and objective Drug fever is frequently misdiagnosed, especially during concurrent infection. Celecoxib causes various adverse effects; however, celecoxib‐induced drug fever is rarely reported. Case summary A 32‐year‐old man presented with pyrexia after 17 days of celecoxib therapy, which was reintroduced following 3‐day total drug cessation. His fever recurred after this unsuspected rechallenge, which aided in the ultimate identification of the offending drug. A Naranjo Score of 8 led us to infer that drug fever was “probably” caused by celecoxib. What is new and conclusion This is the first report of celecoxib‐induced drug fever, aimed at assisting its diagnosis, particularly with rarely suspected causative drugs. As an anti‐inflammatory drug, celecoxib was not readily suspected as a pyrogen. This is the first report of celecoxib‐induced drug fever, aimed at assisting diagnosis of drug fever, particularly with rarely suspected causative drugs.