Urinary tract infections (UTIs) represent the most common cause of bacterial infection in renal allograft recipients. The purpose of this study was to estimate the predisposing factors and the impact of UTIs in the long-term graft function. We studied 122 patients (75 males and 47 females), aged 44 ± 12 years. UTIs occurring during the first month, during the first year, and through the entire follow-up period were analyzed. Diabetes mellitus (DM), delayed graft function, acute rejection episodes, and urinary tract obstruction were evaluated as potential predisposing factors. UTI episodes (n = 316) were recorded in 74 of 122 patients (60.7%). The most common pathogen was Escherichia coli. Most patients (81%) who developed infection during the first month had a new episode in the first year. Hospitalization was necessary in 141 of the 316 UTI episodes whereas 87 were hospital acquired. A strong correlation between female gender and UTI occurrence was found (p = 0.01). Urinary tract obstruction was also related to the UTI occurrence during the first year after transplantation (p = 0.001). Patients' age, DM, delayed graft function, and acute rejection episodes did not correlate with UTI. Long-term renal graft function was not found to be affected by UTI occurrence. UTIs are common infectious complications in renal transplant recipients and often relapse and require hospitalization. The long-term graft function is not affected by the occurrence of UTIs.