The physiological effects of local anaesthetic (bupivacaine), neurolytic (phenol) blockade and surgical ablation of the lumbar sympathetic chain were assessed in patients with peripheral vascular disease or sympathetic dystrophy. Local anaesthetic blockade in 49 patients resulted in significant decrease in pain, plantar sweating and in the vasoconstrictor ice response of the foot, as well as a significant increase in skin temperature and foot blood flow. Subsequent neurolytic blockade in 31 of these patients achieved an effective denervation as assessed by the same physiological measurements. The magnitude of changes in blood flow and sympathetic activity were similar for local anaesthetic and neurolytic blockade as well as in six patients who underwent surgical sympathectomy.