We analyzed the renal radiographic changes in the sickle hemoglobinopathies in 92 patients, in 70 of whom the specific hemoglobin type was documented by electrophoresis. The following conclusions have been drawn: (1) Approximately 50% of patients with SS hemoglobin have renal enlargement (both on roentgenograms and at autopsy), while only a small proportion of patients with the other hemoglobinopathies show renal enlargement; (2) slightly more than one half of patients with each type of hemoglobinopathy have calyceal changes; and (3) these calyceal changes do not fall into a specific pattern with respect to hemoglobin type.