Review of the clinical course, autopsy findings, and sections of the kidneys and pancreas of 214 diabetic patients revealed the presence of intercapillary glomerulosclerosis in 44%, and of hyalinization of the islands of Langerhans in 33%. The lesions occurred together in 21% of the cases. The renal change remains between 30-40% between the ages of 30-70, after which time it rises fairly abruptly. The incidence of the islet change rises steadily from its onset at the age of 20 to equal the glomerular lesion at 70 yrs. of age. Women are more subject to the renal lesion than are [male][male], in a ratio of 107. Diabetic patients with diabetes of more than 6 years'' duration are more subject to intercapillary glomerulosclerosis than those with shorter histories. There is no relation to treatment with insulin. Of the patients with advanced renal lesions, all of whom were diabetics, 83% excreted large amts. of albumin in the urine. Only 30% of this same group, however, developed a true nephrotic pic-ture, with marked edema on a hypoproteinemic basis.