We examined by electron microscopy the calf and buttock skin of 15 juvenile diabetics, 9-36 years old, to determine whether microangiopathy was present. We found in 14 of 15 buttock specimens, and in all 15 calf skin specimens, that the vascular walls were thickened by the peripheral deposition of a belt of basement membrane-like material admixed with variable amounts of collagen (reticulin) fibrils. In addition there appeared to be an increased amount of unidentified material, most likely basement membrane, deposited within the vascular wall itself. We also found age-related elastic fiber abnormalities in the dermis and in the arterioles which were identical to those observed in normal, nondiabetic aged individuals 50-93 years old. We suggest that the vascular and elastic fiber abnormalities in diabetic skin may represent a manifestation of accelerated aging rather than being related to the various underlying metabolic derangements in diabetes.