In a new technique of palpation for renal anomalies in the newborn one hand supports the infant while the fingers of the other hand support the loin and the thumb explores the abdomen. In a series of 11 000 otherwise normal newborn children superficial palpation detected 11 renal anomalies, and deep palpation led to the discovery of another 42 anomalies. One of two other series in which palpation was performed bimanually gave a similar incidence of renal anomalies (0-5%). Early discovery of an asymptomatic anomaly enables early treatment of the complications that are often found in patients with congenital renal anomalies detected in later life.