The purpose of our prospective study was to determine the value of indirect voiding urosonography without the use of contrast-media and without filling of the bladder through a catheter (IVUS) for detection of vesicoureteral reflux (VUR) in children, compared with echo-enhanced voiding urosonography (VUS). Among 57 children (45 girls and 12 boys, aged 2.7 to 12.0 years) admitted for echo-enhanced VUS either as part of routine evaluation after urinary tract infection (UTI) or follow-up of a previously detected VUR, IVUS was also successfully performed in 47 children. The results were considered positive when there was any increase in pelvis size and/or ureter lumen width during voiding. The overall sensitivity of IVUS in the detection of VUR was 49%, specificity 75%. The most accurate results were obtained with VUR grade III, where IVUS correctly detected 6 out of 7 cases, a sensitivity of 86%. The average increase of AP pelvis diameter during voiding was highly significant only in uretero-renal units with VUR grade III. Considering the obstacles in conducting the investigation and its relatively low overall sensitivity and specificity, it seems that IVUS is not sufficiently reliable to replace echo-enhanced VUS.