This report summarizes our 5-year experience with cryosurgery for in situ ablation of liver tumors. The liver was exposed with laparotomy, and the tumors were subjected to two freeze-thaw cycles using liquid nitrogen delivered by insulated probes; cryoablation was monitored with intraoperative ultrasonography. Tumor markers and computed tomography evaluated tumor response during long-term follow-up. From 1985 to 1990, 32 patients (19 men and 13 women) were entered into this study. The histologic characteristics of the tumors were as follows: colorectal, 24 patients; hepatoma, three patients; neuroendocrine, two patients; and others, three patients. After a follow-up period of 5 to 60 months (median follow-up, 24 months), nine patients (28%) remained disease free, 11 patients (34%) were alive with disease, and 12 patients (38%) died. The patterns of failure included liver and extrahepatic disease in 54% of cases, liver disease only in 32% of cases, and extrahepatic disease only in 14% of cases. In patients with "liver only" failure, recurrence at the treatment site occurred in three patients (9%). This study establishes the long-term effectiveness of cryosurgery in the treatment of primary and metastatic liver tumors.