Possibilities of a dynamic segmental diagnostic (DSD-testing) method as a way of testing of autonomic fibers of peripheral nerves in the process of complex examination of patients with diabetes mellitus are considered. Changes in the intensity of skin sympathetic reactions' in patients with diabetic foot syndrome, distal symmetrical sensorimotor polyneuropathy of the lower limbs differed from those in healthy people. A method of DSD-testing is suggested to be used for diagnosis of lesions of autonomic fibers of peripheral nerves in complex examination of patients with diabetes mellitus to predict complications of the disease.