To determine the risk of urinary tract infections in acutely ill febrile children younger than 5 years of age we obtained a urine culture from 664 children presenting to our walk-in clinic with an acute febrile episode. Only 11 children (1.7%) had significant bacteriuria. This figure is similar to the number of children who would be expected to have asymptomatic bacteriuria. These results suggest that pediatricians are not missing the diagnosis of urinary tract infection in febrile children.