A surveillance programme was undertaken to identify all diabetic patients with foot disease in a defined population with the same age and sex structure as that of the UK. Of 1150 diabetic patients identified, 1077 were reviewed either at home or in hospital. The presence of foot deformity, amputation, and foot ulceration was determined. The site, depth, and duration of ulcers were recorded and any previous ulceration noted. All feet with ulcers were X-rayed. A non-diabetic comparison group of 480 age- and sex-matched individuals were also examined by the same observer. The prevalence of past or present foot ulceration was 7.4 (95% CI 5.8-9.0)% in diabetic patients and 2.5 (95% CI 1.1-3.9)% in the non-diabetic group, yielding an odds ratio of 2.94 (95% CI 1.58-5.48) (p less than 0.001) for the occurrence of foot ulceration in diabetic patients. Of the ulcers found on examination, 39.4% were neuropathic, 24.2% were vascular, and 36.4% were mixed. Multiple logistic regression analysis of selected variables revealed that duration of diabetes, absent light touch, impaired pain perception, absent dorsalis pedis pulse, and the presence of any retinopathy were significant predictors of the presence of foot ulcers. The prevalence of amputation in diabetic patients was 1.3 (95% CI 0.6-2.0)%, but there were no amputations in the non-diabetic group.