FOR CENTURIES surgeons have searched for a technique which eliminates pain and bleeding in surgical procedures and reduces postoperative morbidity. Recent experience suggests that cryosurgery produces localized destruction of tissue with little or no discomfort and bleeding during or aftersurgery. Attempts to utilize cold for the destruction of tissue date back to the middle of the 19th century, when an Englishman, James Arnott, applied ice-cold brine to malignant lesions. In America, cryosurgery was first employed in 1939 when Fay attempted to induce subzero temperatures in the brain in the hope of destroying malignant tumors.1 Soon after World War II, Hass and Taylor2 reported extensive investigations with cryogenic lesions in animals and stimulated the development of improved apparatus for the delivery of the cooling medium. Their work was confirmed in 1961 by Tytus and Ries.3 During a series of experiments in animals, these investigators proved that cryosurgery could