Between 1981 and 1987, 300 patients with high grade (III, IV and V international classification) vesicoureteral reflux were treated at a single pediatric hospital. Only patients with primary vesicoureteral reflux were included in the study. The guiding principle during this period was that all patients with high grade vesicoureteral reflux would be observed on prophylactic antibiotics (observational therapy) and surgical correction would be reserved for specific indications. Of the 300 patients 132 received observational therapy alone and 168 required surgical correction for specific indications after varying periods of observation. In both groups the duration of persistent reflux was analyzed using a life-table method. In patients with grade V reflux we observed resolution in 3 patients whereas 23 required surgical correction. Of those patients in the observation group with grade IV reflux 83% had persistent reflux at 2 years and 70% still had reflux at 5 years. For those with grade III reflux the persistence rate was 83% and 50%, respectively. Neither age, sex nor side of reflux had a correlation with the rate of resolution. When tested grade of reflux correlated loosely (p = 0.07). During the period of observational therapy new renal scars developed in 23 patients (8%). We conclude that high grade vesicoureteral reflux can resolve in a minority of patients over a protracted interval. On the basis of this analysis, we advocate consideration of surgical correction in these patients after a 4-year period of observational therapy and for specific indications.