During an 11-year period, 1,069 patients received renal allografts at the University of Minnesota Hospital, Minneapolis, and infections developed in seven (0.65%) due to mycobacteria (Mycobacterium tuberculosis and M kansasii). The primary infection was in joint or subcutaneous tissue in six patients and pulmonary (miliary) in one. Infections in joint or skin shared common features regardless of the species of Mycobacterium and usually mimicked acute pyogenic bacterial infection; all responded to antimycobacterial drugs. The clinical manifestations in our patient in miliary tuberculosis were compared with those of 19 other patients described in the literature. Although their systemic manifestations were more severe, the symptoms were often ill-defined and the diagnosis overlooked. Five of these 20 patients (25%) died of uncontrolled infection.