Urinary tract infections (UTI) are frequent in children, their management is affected by the non-specificity of their manifestations and the uncertainty of the prognosis of UTI, with important sequelae such as renal scarring, hypertension and end-stage renal disease. OBJECTIVE: To determine the epidemiological-clinical characteristics and the initial antibiotic treatment of children with acute pyelonephritis (PNA) treated at the Regional Teaching Hospital of Trujillo from 2002 to 2013. METHOD: 76 children aged 3 months to less than 15 years with a diagnosis of ANP were identified. RESULTS: Frequency of cases of ANP in hospitalized children: 1.36%. Women (76.32%) and men (23.68%). Age group: from 3 months to <2 years (65.79%) and from 2 to <15 years (34.21%). Irrigation factors: previous use of antibiotics (32.9%), previous UTI (17.1%), constipation (13.2%). Clinical manifestations: fever...