Nocardia infections are an important cause of morbidity and mortality in renal transplant recipients. There are no recent studies evaluating the characteristics of nocardiosis using current immunosuppressants. To determine the incidence and risk factors for infection, we performed a 5-year retrospective review and case control study of renal transplant recipients with nocardiosis at 2 renal transplant centers. Four cases of Nocardia infection were identified at each center (incidence of 0.86% and 1.35%). There was no difference between cases and controls in terms of underlying medical conditions, cytomegalovirus-associated infection, or number of rejection episodes. There was a trend toward a shorter time to develop infection with short-course trimethoprim/sulfamethoxazole prophylaxis versus more prolonged prophylaxis (8 months vs. 67 months; P = 0.056) and with tacrolimus-based versus cyclosporine-based regimens (7.8 months vs. 100 months; P = 0.06). Further multicenter studies need to be done to confirm the effects of current immunosuppressant regimens on the incidence and time to develop infections.