We report a case of cutaneous Mycobacterium fortuitum infection occurring in a 53-year-old man with multiple subcutaneous nodules on his right thigh and right lower leg. He has been treated with long-term systemic corticosteroids for his nephrotic syndrome. He had no constitutional symptoms and no lymphadenopathy. Laboratory findigs were within normal limits except for abnormal values for nephrotic syndrome. The skin biospy specimen showed a mixed pattern of epithelioid granuloma with micropseudocyst containing acid-fast bacilli. Methenamine silver stain was negative. The cultures from the skin biopsy specimens on Ogawa media(3％ KH_2PO_4) at 24℃, 32℃, 37℃, yielded colonies of M. fortuitum after 4 days. Culture on Sabouraud media revealed no growth. DOPA reaction was negative. Nitrate reduction test was positive and Tween 80 hydrolysis test was negative. Urine and sputum cultures for atypical mycobacteria were negative. This M. fortuitum was sensitive to amikacin or tetracycline. Four months later, the skin lesions regressed without therapy.