Cryosurgery for the treatment of prostatic disease, a technique that originated in the mid-1960s and was almost abandoned in the mid-1970s, has re-emerged in the 1990s for the treatment of cancer of the prostate. This renewed interest is due to several factors, including the development of intraoperative ultrasound, the refinement of percutaneous access techniques, and improvements in cryosurgical apparatus. The modern technique features the transperineal percutaneous placement of several (generally five or six) metal probes, each 3 mm in diameter, in the prostate under ultrasound guidance. After insertion, the probes are cooled in a manner that produces complete freezing of the prostate and, if required, extraprostatic extensions of disease. The freezing process is monitored by ultrasound, which provides an image of the boundary of freezing as it advances through the prostate and thereby provides control of the extent of freezing. This review describes the historical background of prostatic cryosurgery and the current status of this new procedure, including the important issues of case selection, technique, and results. The recent nature of this experience precludes judgment of long-term merit, but the favorable short-term results of cryosurgical ablation of the prostate encourage further selective use of this technique in the treatment of prostate cancer. Definition of appropriate patient selection and optimal technique are needed to improve treatment by cryosurgery.