There has been a recent report of five children with the Russell-Silver syndrome. It was suggested that the clinical features were well-established, and the only laboratory investigation necessary was a fasting blood glucose to exclude hypoglycemia. This study is a review of the status of the genitourinary system in six patients with the Russell-Silver syndrome. Four had abnormal excretory urograms or cystograms. These abnormalities included bilateral chronic pyelonephritis, unilateral ureteralpelvic obstruction and severe reflux, and unilateral pyelonephritis. The finding of significant potentially treatable anomalies in the genitourinary system of patients with Russell-Silver syndrome indicates that an intravenous pyelogram and cystogram be included in the investigation of these patients.