Disseminated tuberculosis occurred in 2 allograft recipients of kidneys procured on the same donor. Both recipients were treated by low dose prednisolone and azathioprine, and one of them was on a special protocol including antilymphocyte globulins as rejection prophylaxis. None of them experienced acute rejection. The early posttransplant period was uneventful except for the occurrence of mild viral infections in both cases (herpes simplex virus in case 1 and cytomegalovirus in case 2). 2 and 6 months after transplantation, respectively, patient 1 developed acute fever, asthenia, and disorientation while patient 2 presented with spiking fever and miliary pneumonitis. Mycobacterium tuberculosis grew in the urine of both recipients in the absence of clinical genitourinary symptoms. The two mycobacterial species had the same bacteriologic characteristics and the same antibiotic sensitivity. As the recipients had no evidence of a previous history of active tuberculosis, it is suggested, as for some other infectious agents, that mycobacterium was transmitted along with the transplanted kidneys.