PURPOSE: Urinary tract infection (UTI) caused by gram-positive uropathogens is usually hospital-acquired and associated with predisposing conditions. However, the incidence of gram-positive bacteria in community-acquired UTIs has recently increased worldwide. We aimed to investigate the clinical significance of UTI and associated genitourinary malformations in young children with febrile UTIs caused by gram-positive bacteria. METHODS: We retrospectively reviewed the medical records of 566 patients (age, <1 year) who visited the Korea University Medical Center for febrile UTIs between January 2008 and May 2013. We classified the patients into the following two groups: gram-positive (P group) and gram-negative (N group), according to the results of urine culture. The fever duration; white blood cell (WBC) counts and C-reactive protein (CRP) levels in peripheral blood; and the presence of hydronephrosis, cortical defects, vesicoureteral reflux (VUR), and renal scarring were compared between the two groups. RESULTS: The number of patients with gram-positive bacteria was 23 (4.1%) and with gram-negative bacteria was 543 (95.9%). The most common pathogen was Escherichia coli, and Enterococcus faecalis showed the highest incidence among gram-positive uropathogens. Patients with gram-positive bacteria showed longer fever duration compared to that in patients with gram-negative bacteria (P vs. N, 3.4+/-1.2 vs. 2.9+/-1.6 days, P<0.05). The incidence of VUR was increased in the gram-positive group compared to that in the gram-negative group (P vs. N, 55.6 vs. 17.8%, P<0.05). However, there were no significant differences in other laboratory and radiologic findings. CONCLUSION: The findings of our study show that community-acquired UTIs in patients younger than 1 year of age, caused by gram-positive uropathogens, can be associated with prolonged fever duration and the presence of VUR.