The aim of the present study was to obtain data on the outcome of children with persistent vesicoureteral reflux (VUR) after cessation of antibiotic prophylaxis. Children with VUR who had been on antibiotic prophylaxis for at least 2 y and were free of urinary tract infections (UTI), had normal voiding patterns, and no hydronephrosis or new kidney scarring, had antibiotic prophylaxis discontinued, were followed up prospectively with urine cultures, voiding cystourethrography, and technecium-99m dimercaptosuccinate renal scintigraphy. The findings were compared with those of the same patients while they were on antibiotic prophylaxis. In 54 children (39 girls and 15 boys), antibiotic prophylaxis was discontinued. The mean follow-up time on and off antibiotic prophylaxis was 4.4+/-2.1 and 4.4+/-2.2 y, respectively. Nine UTI episodes occurred during the on- and 8 during the off-prophylaxis period. In 80 of 96 and in 68 of 74 ureters the reflux resolved or downgraded during the on- and off-prophylaxis periods, respectively. No new scar lesions were detected in any of the children. In conclusion, in children with persistent VUR and certain characteristics, antibiotic prophylaxis can be safely discontinued.