The following parameters were determined in 20 diabetics with chronic obliterating arteriopathy of the lower extremities: C-HDL, apo-A1, apo-B, triglyceridaemia, the glycaemic profile and HbA1c oscillometry, photoplethysmogram and claudication distance on a treadmill. Examination of the results obtained did not show any variation in the lipoproteic picture and only an improvement, in some subjects, in claudication distance. It is therefore hypothesised that in diabetic C-HDL and apo-A1 are not predictive of atherosclerotic risk although it cannot be excluded that changes in such constants may represent a synergetic factor in determining arteriosclerosis.