We report a case of blastomycosis presenting as epididymitis and prostatitis. The diagnosis was suggested by pathologic findings in the prostate and epididymis and was further supported by serology. The diagnosis was confirmed by culture and special staining. Long-term cure was accomplished after a 12-month course of oral ketoconazole (400 mg/day). Therapy was monitored by culture and serology. Blastomycosis is an unusual but significant pathogen which occasionally presents with genitourinary tract involvement. Effective diagnostic and oral treatment regimens are now available but are dependent on a high degree of suspicion in cases of chronic prostatitis or epididymitis.