The occurrence of unusual renal lesions in 2 siblings, the second and fourth child of a young Yemenite woman, is reported. One of the siblings, a male infant, died 48 hours after birth and multiple metanephric hamartomas were found in his normal‐sized kidneys. The second sibling, a stillborn delivered 3 years later, had both kidneys enlarged by multiple nodules of neoplastic nephrogenic tissue similar to that observed in Wilms' tumor and corresponding to the picture of diffuse nephroblastomatosis. The presence of these 2 lesions in siblings may be considered as support for the origin of Wilms' tumor from embryonic nephrogenic tissue.