BACKGROUND: Blastomycosis is an uncommon male-predominant disease caused by the fungus Blastomyces dermatitidis. The lungs are most commonly affected, and other organs are usually involved by dissemination. Clinical feature and pathohistologic findings are similar to the appearance of squamous cell carcinoma. METHODS AND RESULTS: A 52-year-old male patient who has lived as a farmer on the countryside in Argentina for 35 years presented with an initial histopathologic diagnosis of a squamous cell carcinoma of the right lower jaw. There was no history of pulmonary disease, in particular fever, coughing, or hemoptysis. Final pathohistologic evaluation after resection revealed B. dermatitidis infection. This article presents the first described case of oral manifestation of B. dermatitidis infection in Switzerland. CONCLUSIONS: Manifestation of blastomycosis in oral tissue can mimic the feature of a squamous cell carcinoma and can therefore be a diagnostic pitfall that head and neck surgeons and a pathologist should be aware of.