We report a case of a 28-year-old immunocompetent man with a left foot swelling and pain of 3 weeks' duration. He was initially treated with antibacterial agents for cellulitis. Lack of clinical improvement with concomitant reticulonodular infiltrates on chest x-ray prompted further work up including magnetic resonance imaging, bone biopsy, and bronchoalveolar lavage. Cultures and histopathologic examinations from lung and bone specimens revealed Blastomyces dermatitidis. He was successfully treated with oral itraconazole for 1 year. Osseous blastomycosis can mimic an acute pyogenic infection. A high index of suspicion should be kept in mind for this infection, especially in patients presenting from endemic areas.