Hepatic radiofrequency ablation (RFA) is effective in treating patients with unresectable hepatic malignancies.Case series of 123 patients with unresectable hepatic tumors or tumors with histological findings not traditionally treated by means of hepatic resection were considered for hepatic RFA. Median follow-up was 20 months.Tertiary referral center.The 123 patents underwent 168 RFA sessions from January 1, 1998, through September 30, 2001. Sixty-nine patients were male and 54, female; average age was 65 years (range, 1-89 years). Fifty-two patients had metastatic colorectal cancer; 30, hepatocellular carcinoma; and 41, cancers with other histological findings.A 200-W, cooled-tip RF probe system was used for all cases. Probe placement and ablation were monitored by means of real-time ultrasonography or fluoroscopic computed tomography. Final tissue temperature of greater than 50 degrees C was achieved in all cases.Initial treatment sessions were percutaneous in 87 patients, open operations in 33, and laparoscopic in 3. Repeated sessions were percutaneous in all but 2 patients. The mean number of lesions treated per session was 2.7 (range, 1-24). Mean tumor size was 5.2 cm (range, 0.5-15.0 cm). One death occurred within 30 days of a procedure. No hepatic bleeds, bile leaks, or adult respiratory distress syndrome occurred. Overall morbidity was 7.1%. Complications included hepatic abscesses in 4 patients, transient liver insufficiency in 3, segmental hepatic infarcts in 2, diaphragm paralysis in 1, hepatic artery-to-portal vein fistula in 1, and systemic hemolysis in 1.Hepatic RFA is an effective treatment option for patients with unresectable hepatic malignancies. Careful patient selection based on tumor size, location, and number and on patient clinical status should determine the choice of treatment. Further controlled trials are needed to determine the effect of hepatic RFA on long-term survival.