BackgroundTumor necrosis factor alpha (TNF‐α) inhibitors have revolutionized treatment of many inflammatory diseases. Sinusitis after initiation of TNF‐α inhibitors has been observed, but has not been well described in the literature. We aim to characterize the clinical features of sinusitis in patients on anti‐TNF‐α therapy.MethodsThis is a retrospective chart review of 28 patients on a TNF‐α inhibitor diagnosed with sinusitis by otolaryngologists at Duke University. Patient demographics, sinusitis characteristics, and treatment course were studied by chart review.ResultsThe prevalence of sinusitis diagnosed and treated by an otolaryngologist was less than 1%. Of the 28 patients studied, 12 (42.9%) had a history of preexisting sinusitis and 16 (57.1%) had new‐onset sinusitis. 71.4% were diagnosed with chronic rhinosinusitis without polyps (CRSsNP), with disease mainly involving the maxillary and ethmoid sinuses. No patients had major extrasinus complications or required hospital admission or intravenous (IV) antibiotics. 35.7% (n = 10), including 44% (7/16) of new‐onset patients required a surgical intervention after initiating anti‐TNF therapy. 14.3% (n = 4) of the cohort had improvement in sinonasal symptoms after stopping, changing, or holding doses of the TNF‐α inhibitor.ConclusionAnti‐TNF‐α therapy can be associated with new‐onset sinusitis, mainly CRSsNP. Overall, the percentage of patients on a TNF‐α inhibitor seeking consultation from an otolaryngologist is low. While some patients with new‐onset sinusitis will require surgery, modification of anti‐TNF‐α therapy should be considered as an option in the medical management of these patients.