The prevalence of lower limb neuropathy was determined in a known diabetic population. From a general population of 97,034 subjects, a total of 1150 diabetic patients were identified of whom 1077 (93.7%) were reviewed. Neuropathy was defined as symptoms plus one abnormal physical finding, or two abnormal physical findings. An age- and sex-matched non-diabetic control group of 480 individuals was also examined by the same single observer. The prevalence of neuropathy was 16.3 (95% CI 14.6-19.0)% in diabetic patients and 2.9 (95% CI 1.4-4.4)% in non-diabetic subjects, yielding a prevalence odds of 6.75 (95% CI 3.87-11.79), p less than 0.001. In Type 1 diabetes, the prevalence was 12.7 (95% CI 8.0-17.6)% and in Type 2 diabetes 17.2 (95% CI 15.9-18.5)%. After adjusting for age, the difference was not significant (odds ratio (OR) 1.60 (95% CI 0.95-2.76)). The prevalence of neuropathy increased with age in diabetic and non-diabetic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)