Introduction: Diarrhoea is responsible for nearly 18% of total deaths in children. In early childhood, symptoms of diarrhoea may be similar to urinary tract infection (UTI). This study was designed to determine the prevalence of UTI and its antibiotic sensitivity in children hospitalized with acute diarrhoea. Methods: All cases of acute diarrhoea aging 1-60 months and hospitalized in 2009-2011 in Abuzar children’s hospital (the main referring educational hospital in southwestern Iran) were enrolled. They were included if diarrhoea lasted <14 days, stool passage >3 times a day and antibiotics were not used in the past two days. Sensitivity and resistance of cultures were evaluated for common antibiotics. Results: Out of the total 575 subjects, 31 (5.4%; 18 males ≈ 58%, 13 females ≈ 42%) were confirmed to have a UTI. There was no sex difference (P=0.012), but 77.4% of the subjects were <12 months of age (P=0.012; OR=2.89). The results of urine culture were reported as follows: 27 cases (87.1%), Escherichia coli; two (6.5%), Enterococcus; one (3.2%), Pseudomonas; and one subject (3.2%), Klebsiella. Antibiotic sensitivity was found to be 93.5% to Nitrofurantoin, and 61.3% to Ceftriaxone and Nalidixic acid. They were resistant in 67.7% to Co-trimoxazole and 64.5% to Gentamicin. Conclusion: Although UTI is not so much frequent in childhood acute diarrhoea, it must be considered especially in infancy.