It has been suggested that thick skin on the dorsum of the hands and fingers is a common finding in diabetes mellitus, and that affected persons have an increased prevalence of diabetic retinal microvascular disease. Using high resolution ultrasonography, we were able to quantitatively demonstrate increased skin thickness on the hands and feet of many of our diabetic patients. In our limited series, however, there was no correlation with retinal disease. The general occurrence of thick skin on the extremities of persons with diabetes mellitus is apparently independent from the thick skin syndromes which are associated with disease complications.