Controversy has surrounded the role of local hypothermia as a preoperative treatment in amputations of the lower extremity. A study was undertaken to determine the effectiveness of amputation under cryoanesthesia in decreasing postoperative morbidity and mortality in below-knee (BK) amputations. Of 154 BK amputations, only 91 with unreconstructable vascular disease, gangrene, or both, were included in this study. Group I consisted of 48 patients (mean age 63.9 years) who had undergone a routine BK amputation; group II consisted of 43 patients (mean age 65.7 years) who were acutely ill and too unstable to undergo a major surgical procedure. Group II patients were treated by amputation while under cryoanesthesia before any definitive operative intervention. The patients in group II were significantly (p less than 0.05) more ill preoperatively than those in group I. Group II patients had a higher prevalence of previous myocardial infarction, previous stroke, diabetes mellitus, osteomyelitis, and wet gangrene. Seventy percent of the patients in group II had three or more risk factors vs. 46% in group I. Early postoperative mortality rates did not differ significantly between groups (group I, 8%; group II, 9%); the average length of hospital stay for group I patients was 24.2 days compared with 17.7 days in group II. Group II patients sustained slightly more postoperative complications. Amputation under cryoanesthesia appears to be of value in reducing postoperative morbidity and mortality and length of hospital stay in the acutely ill patient with unreconstructable vascular disease, gangrene, or both.