A matched-pair case-control study was done on 4 groups of renal transplant patients who acquired nosocomial infections: 1) urinary tract infection, 2) postoperative wound infection, 3) urinary tract plus postoperative wound infection and 4) the entire group of patients. For urinary tract infection patients a prolonged period of hemodialysis before hospitalization was considered a risk factor. Renal transplantation with an HLA-1 (identical) donor graft was a characteristic related to the control group. High levels of plasma creatinine and prolonged vesical catheterization were risk factors for acquiring postoperative wound infection. The latter was also considered to be a risk factor for both infections, as well as the inadequate use of antibiotic prophylaxis and the number of antibiotics used. For the entire group of patients surgical wall hematoma was a risk factor. In this group the independent risk factors analyzed by multivariate logistic regression were renal transplantation with a cadaver donor graft, prolonged vesical catheterization and prolonged use of antibiotics. Careful management of the cadaver donor allograft, decreasing the changes of contamination, decreasing the interval of urinary catheter maintenance and use of antibiotics in the postoperative period are measures that can contribute to lessen the incidence of these nosocomial infections in renal transplant recipients.