Sympathectomy has been advocated in the therapy of acute frostbite because ischemia is one determinant of injury severity. Among 66 frostbite victims treated from 1976 through 1978, a group of 15 patients with acute, bilaterally equal injuries judged to be third or fourth degree were treated with immediate intra-arterial reserpine (IAR) in one limb and ipsilateral sympathectomy. Three additional patients who were excellent candidates underwent immediate sympathectomy. The average interval from injury to IAR injection was 3 hours (range 1 to 24 hours). The average interval from injury to sympathectomy was 3 days (range, 12 hours to 10 days). Efficacy of therapy was assessed by comparison of the sympathectomized limbs to the contralateral untreated limb. There was no conservation of tissue, resolution of edema, pain reduction, or improved function in sympathectomized limbs compared with those treated with IAR. One patient demarcated more rapidly and one other patient appeared to be protected from recurrent injury. Sympathectomy was not effective therapy for acute frostbite even when achieved early with IAR. Late protection against subsequent cold injury appears to be the only benefit of sympathectomy for frostbite.