In a consecutive series of patients with ulceration of the lower leg referred to the dermatological in-patient department during a 9-month period, a systolic digital blood pressure level (SDBP) below 60 mmHg was used to identify patients with complicating arterial occlusive disease (AOD) of the legs. AOD was diagnosed in 25 patients and stasis ulcers from venous disease (SDBP greater than or equal to 60 mmHg) in 38 patients of the same ages. Patients with ulceration from other causes were excluded. After 1 year, 48% of the patients with AOD and 5% of those with stasis ulcers had died. In the AOD group, 11 legs were amputated. Our figures show that the SDBP is valuable in identifying high-risk patients.