Risk factors for vibratory perception threshold abnormalities were studied in 200 diabetic patients between the ages of 21 and 70 years and 62 control subjects of similar age. Vibratory perception (measured with the Biothesiometer) was absent over one or both halluces in 18 percent of the patients. In a stepwise multiple logistic regression analysis, height was the variable most strongly associated with absent vibratory perception (coefficient +/- SE, 0.501 +/- 0.097/inch; p less than 0.0001). Duration of diabetes (p less than 0.001), age (p less than 0.05), and ethanol use (p less than 0.05) were also associated. The prevalence of absent vibratory perception in the lower, middle, and upper thirds of the height distribution was 0.05, 0.08, and 0.40, respectively. Among the control subjects, there was no association of vibratory perception with either height or ethanol use. These data strongly suggest that body stature is a major risk factor for diabetic sensory neuropathy.