Actinomycosis is a chronic granulomatous disease caused by the fungus Actinomyces israelii, and is characterized by suppuration, abscess formation, and eventually the development of multiple drainage sinuses. The number of lesions that mimic actinomycosis of the lung is extensive. We report a case of a 60-year-old women who presented with chronic cough and profuse sputum. The sputum acid-fast stain showed positive (one plus) and the culture yielded nontuberculous mycobacterium. Fiberoptic bronchoscopy revealed an endobronchial tumor with stenotic bronchus. Histologic examination of the biopsy specimen demonstrated Actinomyces infection. There was a clinical response to penicillin therapy.