21 patients with diabetes mellitus (DM) type 1 and 97 patients with DM type 2 (a total of 118 diabetics) complicated by angiopathy of the lower limbs and diabetic retinopathy (n = 96) received sugar reducing drugs and ozone-oxygen therapy (OOT). Three techniques of OOT were used: external ("ozone boot" method), systemic (intravenous introduction of ozone-inriched physiological solution or rectal insufflations of ozone-oxygen mixture), combined (external + systemic). The external and combined methods proved superior in trophic disorders in the region of distal parts of the lower limbs while the systemic and combined methods produced better effect on the other signs of diabetic angiopathy and retinopathy, functional and biochemical parameters.