PURPOSE: This retrospective study evaluates the applicability of a selective approach for imaging in children aged 0-15 years with a first episode of pyelonephritis, based on the UTI guidelines of the National Institute for Health and Clinical Excellence (NICE). MATERIAL AND METHODS: A total of 96 consecutive patients were included (age range: 0.1-14.9 years, median age: 0.7 years), treated for a first episode of confirmed culture-positive pyelonephritis. At initial hospitalization all patients underwent ultrasound examination of the kidneys and urinary tract (US) and technetium-99m mercaptoacetyltriglycine scinti- and renography ( (99m)Tc MAG3). If vesicoureteral reflux (VUR) was suspected, then prophylactic antimicrobial therapy was prescribed and the patients were referred to a surgeon for further evaluation including voiding cystoureterography (VCU). Patients with known urological anomalies including antenatally diagnosed anomalies were excluded. All patients were followed up for a median of 5.2 years (3.5-8.6 years). RESULTS: Initially, US findings were abnormal in 29 (30%) patients and (99m)Tc MAG3 findings were abnormal in 20 (21%) cases. At follow-up, prophylactic antimicrobial therapy was prescribed for 19 (20%), and VUR was diagnosed by VCU in 9 patients. Surgery was carried out in 7 (7%) patients, primarily for VUR. If the NICE guidelines had been initially followed, 5 of our 9 patients with VUR would not have been identified. VUR surgery was performed in 4 of these cases. Moreover, 9 cases with urological anomalies subsequently prescribed prophylactic antimicrobial therapy would have been missed. CONCLUSION: We do not recommend following the imaging strategies of the NICE guidelines for children with a first episode of pyelonephritis. Our most important argument is that at follow-up, after a minimum of 3.5 years, the initial diagnosis of VUR would have been missed in 4 out of the 5 patients who underwent VUR surgery.