A case of acute renal vein thrombosis diagnosed preoperatively on the fourth day of life and cured by nephrectomy is recorded. It is believed that this is the youngest survivor of surgical therapy for this condition. In this case, a hydrocele on the side of the renal lesion appears to be a newly observed associated finding, possibly related to irritation and serositis of the peritoneum overlying the affected kidney. The reports of surviving patients recorded in the literature since 1900 are reviewed and discussed.