Objective: Antibiotic resistance against bacterial pathogens associated with urinary tract infections (UTI) is rapidly increasing worldwide. In this study, we aimed at determining the causative microorganisms in children under 17 years of age diagnosed with UTI in our hospital and the antibiotic resistance rates of these causes. Methods: We isolated and retrospectively analyzed 4801 urine samples of children under 17 years old who presented with bacterial growth in their urine cultures. The isolated bacteria and their antibiotic resistance profiles were statistically analyzed. Results: Most (2001/77.2%) of 2592 patients included in the study were female and the mean age and median interquartile range (IQR) was 55 (12-98) months. Except for the neonatal period, the female gender was predominant in all age groups (p<0.0001). The most frequently isolated bacteria included Escherichia coli (67.7%), Klebsiella spp. (10.7%), and Enterococcus spp. (8.8%). The most and least resistant antibiotics were ampicillin (66.6%) and meropenem (0.3%) for E. coli, respectively. Although resistance of E. faecalis to ampicillin and ciprofloxacin is at a low level, E. faecium is much more resistant to these antibiotics (p<0.0001). Conclusion: It is important that each center determines its own resistant antibiotics so as to guide empirical treatment. Re-evaluating each antibiotic that is started to be used empirically according to the results of culture and sensitivity in addition to switching to a suitable antibiotic would be very effective in reducing resistance rates.