Tuberculosis (TB) is an important infection encountered after transplantation especially in developing countries. In this report, we studied the risk factors and impact of TB on the outcome of kidney transplantation. We retrospectively analyzed the cases of TB infection in a series of 1600 renal transplants carried out in our center from March 1976 to March 2004. Demographic parameters and clinical antecedents such as age, cause of ESRD, previous renal function, type of immunosuppression and the duration to develop the TB infection were considered. Moreover, the clinical onset, diagnostic tools, treatment policy and evolution were studied. Diagnosis was made with the Ziehl–Neelsen staining method and PCR for TB antigens and confirmed by culture method. In the course of an 18 year period, there were 71 cases of posttransplant TB (a prevalence of (4.4%). The mean elapsed time from the transplantation was 61.5 months; the infection appeared in 7 patients during the first year after transplantation. The clinical onset was urinary infection in 43 cases (60.5%); 21(29.6%) had pulmonary infection; 6 cases had disseminated infection. Most of patients were CsA treated. Before tuberculosis onset, 44 patients experienced one or more episodes of acute rejection and were treated with steroid pulses, ATG or OKT3. At the time of an infection, the graft function was normal in 51 patients and chronic graft nephropathy was evident in 19 patients (Cr 2.5-5 mg %). All post transplant TB patients received triple antituberculous therapy (rifampicin, ethambutol and INH) with favorable microbiological response except in two who need another course for 24 months. Throughout the follow-up period, the graft function remained stable in 42 patients (59%). Although 3 patients recovered, progressive graft failure developed and hemodialysis was restarted in 27 patients. Hepatotoxicity was seen in 14 patients, mild in 11 with normalization of a temporarily withdrawal of rifampicin, and severe in 3 patients but with no mortality attributable to hepatocellular failure. Twenty one patients died, 19 of them due to causes not related to TB or its treatment. TB is a common infection in renal transplant recipients with a peak incidence after the first year. Urinary TB infection is more prevalent in our transplant population which necessitate through evaluation of both recipients and donor. Chronic rejection is a serious complication in these patients which had a negative impact on the graft survival especially in CsA treated recipients.