In the diabetic patient the clinical manifestations of peripheral neuropathy occur more commonly in the distributions of longer neurons. Utilizing height as a proxy variable, we have examined whether neuron length is also a determinant for the occurrence of peripheral neuropathy among diabetic patients. In studies performed at two sites (Sheffield and Miami) the heights of diabetic patients with symptomatic peripheral neuropathy were compared with those of non-neuropathic diabetic patients. At each site the neuropathic patients were significantly taller (P = 0.02 for Sheffield and P = 0.01 for Miami). These data were not biased by age or race. Body stature (as a proxy for neuron length) appears to be a constitutional risk factor for diabetic peripheral neuropathy.