We report a case of pulmonary Mycobacterium fortuitum infection with multiple nodular shadows. A 52 year-old male was admitted complaining of fever and chest abnormal shadows. He didn't have pulmonary or systemic underlying diseases. Chest radiograph and computed tomography scan showed multiple nodular shadows in the both lung fields. Isoniazid, rifampicin and ethambutol were administered based on the presumptive diagnosis of tuberculosis. Cultures of the sputum and bronchial washing fluid were repeatedly positive for M. fortuitum, and the case was diagnosed as pulmonary M. fortuitum infection. Although the in vitro susceptibility was resistant to isoniazid, rifampicin and ethambutol, abnormal shadows on the X-ray showed improvement by the combined use of INH, RFP and EB. There are no signs of recurrence after completion of the treatment for 12 months.