To determine the causative agents of urinary tract infections (UTIs) among renal transplant recipients and to compare the antibiotic susceptibilities of Escherichia coli strains isolated from complicated community acquired UTIs and renal transplant recipients. We evaluated 75 episodes of 63 recipients with confirmed UTI. To compare the susceptibility rates of E. coli, 226 isolates from non-transplant patients with complicated communityacquired UTIs were also evaluated. Ten episodes (13.3%) occurred in the first month following the transplantation, 11 (14.7%) in the period of the second month to sixth month and 54 (72%) occurred six months after transplantation. Forty six (61.3%) of the 75 isolates were Escherichia coli. Among the E. coli isolates, ciprofloxacin resistance rates were 50% (2/4) in the first month after transplantation, 75% (6/8) in the period of the second month to sixth month, and 32.4% (11/34) 6 months after transplantation. The resistance rates of TMP-SMX in the same time periods were 100% (4/4), 87.5% (7/8), and 70.6% (24/34), E. coli is the most frequently isolated organism from UTI in renal transplant recipients. The rates of resistance to TMP-SMX, ampicillin, gentamicin among E. coli isolated from renal recipients are significantly higher than those in community-acquired complicated UTIs. The increased resistance of urinary pathogens to TMPSMX is a major concern. Although high resistance rates of ciprofloxacin against E. coli strains were determined in this group, it was not found to be statistically significant.