We report a case of broncholithiasis secondary to pulmonary actinomycosis. Broncholithiasis has occasionally been reported in association with actinomycosis, but it is unclear if actinomycosis leads to lymph node calcification with subsequent erosion into the airway, producing a broncholith, or if an existing generic broncholith is secondarily colonized with Actinomyces. The patient had postobstruction pneumonia, and computed tomography showed calcified nodules obstructing the bronchus intermedius and distal necrotizing pneumonia. The nodules included sulfur granules containing Gram-positive branching filamentous organisms consistent with Actinomyces. The finding of Actinomyces throughout the broncholith is strong evidence that the etiology of the broncholithiasis was a primary pulmonary Actinomyces infection.