In order to investigate the effect of freezing liver cancers, cryosurgery was performed on solid liver tumors in rats. 8 of 21 Sprague-Dawley rats with single liver implants of Walker-256 tumor were apparently cured of these cancers by cryotherapy. Two others had liver cancer controlled, but had spread of cancer to other parts of the body. There was one operative death (not included in data), but no other serious complication from the procedure.