Background: The co-occurrence of bronchiolitis and urinary tract infections (UTI) in hospitalized children is associated with high morbidity and economic strain. However, due to a low prevalence (<3%) and inconsistent diagnostic criteria, there is ongoing debate regarding the necessity of systematic screening. This study estimated the prevalence of UTI among children admitted for bronchiolitis and analyzed the associated demographic and clinical factors. Methods: A 5-year (2016-2020) retrospective chart review was conducted among all children admitted for bronchiolitis at a referral pediatrics department in Jeddah, Saudi Arabia. UTI was diagnosed according to the American Association of Pediatrics criteria. Demographic, clinical, microbiological, and imaging data were extracted from the hospital electronic records. Results: Of the 491 cases of children with bronchiolitis, urine culture and analysis were available for 320 patients. Based on urine culture criteria alone, the prevalence of UTI was 13.1% (95% CI 9.6-17.3), and the most common pathogens included E. coli (33.3%), K. pneumoniae (23.8%), and Enterococcus faecalis (14.3%), and 13 (31.0%) of the isolates were EBSL. By considering urinalysis criteria, i.e., pyuria or nitrituria, the estimated prevalence of UTI decreased to 3.4% (1.7-6.1%), and the most common pathogens were K. pneumoniae (5/11) and E. coli (3/ 11), with 6/11 ESBL-producing isolates. Regurgitation associated with a higher risk of UTI compared to absence of regurgitation (5.3% versus 0.8%; p = 0.031). Urinary tract ultrasound showed high specificity (98.7-100%) and negative predictive value (97.4-97.7%) in UTI using either criterion. Conclusions: There is a higher prevalence of UTI among children with bronchiolitis in the study center, which has several implications in screening, diagnosis, and management. Further multicenter studies are required to enhance the external validity of these findings and assess the cost-effectiveness of screening strategy at a national level.