Our study was done on the outpatients and inpatients of Ankara Numune Hospital who were diagnosed as having urinary tract infections. When 301 cultures with positive results were evaluated. Gram-negative bacteria were found most frequently (E. coli 45.2%, Klebsiella 23.2%, Enterobacter 16.6%, Proteus 11.5%, S. aureus 2.2%, Pseudomonas 1.3%). By using the disc diffusion method, the effectiveness of antibiotic discs of amikacin, tobramycin, netilmycin, cephoperazone, cephotoxime, cephtizoxime, cephradine, cephuroxime, carbenicillin, piperacillin, ofloxacin, nalidixic acid and sulbactam/ampicillin on the isolated strains were investigated. Ofloxacin (92.35%), cephotaxime (72.6%) and nalidixic acid (62.10%) were found to be the most effective while cephradine (7.96%), carbenicillin (11.8%) and piperacillin (14.96%) were found to be the least effective antibiotics.