Cryosurgery, also called cryotherapy and cryoablation, has made noteworthy progress since 1990 when intraoperative ultrasound became available to monitor the process of tissue freezing. In these few following years, new cryosurgical apparatus became available, techniques were improved, and imaging methods were further developed. A better understanding of the mechanisms of tissue injury from freezing was achieved and the potential usefulness of adjunctive therapy to improve the efficacy of cryosurgery was recognized.