We have undertaken a prospective study of the presentation of all 669 ulcers seen in a specialist multidisciplinary foot clinic between 1 January 1993 and 1 August 1996, with particular reference to the factors which precipitated ulceration as well as to any delays in referral. Nearly two-thirds (61.3%) of all lesions were first detected by the patient or a relative, and the remainder by a healthcare professional. The median (range) time which elapsed between ulcer onset and first professional review was 4 (0-247) days, and the median time between first review and first referral to the specialist clinic was 15 (0-608) days. Significant delays were judged to have occurred in 39 instances. The most common precipitant of ulceration was rubbing from footwear, which was responsible for 138 (20.6%). Fifty-eight (8.7%) were the result of immobilization from other illness, and a further 24 were the consequence of surgery. Overall, professional factors contributed to the development or deterioration of 106 lesions (15.8% total). These results should form the basis of strategies designed to minimize the onset of ulceration in those known to be at risk: educational strategies need to be directed at professionals as much as at patients.