PURPOSE: To present early results of cryosurgical ablation of prostate cancer with an ultrasound-guided percutaneous technique. MATERIALS AND METHODS: Cryosurgery was performed in 210 patients; near complete 3- and 6-month follow-up data were available for 130. Androgen ablation therapy was used to decrease the size of the prostate gland for optimal freezing. Prostate-specific antigen (PSA) and prostatic biopsy studies were performed at 3, 6, and 12 months. RESULTS: Gland volume decreased from 29 cm3 +/- 14.1 to 20.4 cm3 +/- 8.4 (P < .0001) after androgen ablation. Rates of positive biopsy findings at 3, 6, and 12 months were 7.7%, 3.3%, and 2.3%, respectively. Serious complications were minimal and included no deaths, urethrorectal fistulas in five patients, and total incontinence in three. Mean PSA levels decreased from 12.6 +/- 16.1 preoperatively to 0.35 +/- 0.75 at 3 months, 0.54 +/- 1.1 at 6 months, and 0.43 +/- 0.78 at 12 months (persistent cancers excluded). CONCLUSION: These preliminary results demonstrate that cryosurgery can cause necrosis of prostate cancer. Long-term results and randomized trials are necessary to determine if this means longer disease-free intervals and increased patient survival compared with results of current therapeutic methods.