We investigated the risk factors for community acquired/onset urinary tract infections due to extended spectrum beta-lactamase (ESBL)-positive Escherichia coli or Klebsiella pneumoniae in 62 patients who were followed-up from August 1, 2003 to September 1, 2006. Sixty patients with community-acquired urinary tract infections caused by ESBL-negative E. coli or K. pneumoniae who were followed-up during the same dates were included as a control group. Age (>= 65 or <65 years old), sex, bladder cancer, benign prostate hypertrophy (BPH), prostate cancer, urolithiasis, urethral catheter, previous urological operation, diabetes mellitus, use of antibiotics during the last 3 months and hospitalization during the last 3 months were investigated as risk factors. The presence of previous urological operation and quinolone or cephalosporin use for any infection during the last 3 months were found to be independent risk factors. Knowing the risk factors for community acquired/onset urinary tract infections caused by ESBL-positive E. coli or K. pneumoniae is of great importance in planning empirical antibiotic therapy.