To examine recurrence and survival rates for patients treated with hepatic resection only, radiofrequency ablation (RFA) plus resection or RFA only for colorectal liver metastases. Thermal destruction techniques, particularly RFA, have been rapidly accepted into surgical practice in the last 5 years. Long-term survival data following treatment of colorectal liver metastasis using RFA with or without hepatic resection are lacking. Data from 358 consecutive patients with colorectal liver metastases treated for cure with hepatic resection +/- RFA and 70 patients found at laparotomy to have liver-only disease but not to be candidates for potentially curative treatment were compared (1992-2002). Of 418 patients treated, 190 (45%) underwent resection only, 101 RFA + resection (24%), 57 RFA only (14%), and 70 laparotomy with biopsy only or arterial infusion pump placement ("chemotherapy only," 17%). RFA was used in operative candidates who could not undergo complete resection of disease. Overall recurrence was most common after RFA (84% vs. 64% RFA + resection vs. 52% resection only, P < 0.001). Liver-only recurrence after RFA was fourfold the rate after resection (44% vs. 11% of patients, P < 0.001), and true local recurrence was most common after RFA (9% of patients vs. 5% RFA + resection vs. 2% resection only, P = 0.02). Overall survival rate was highest after resection (58% at 5 years); 4-year survival after resection, RFA + resection and RFA only were 65%, 36%, and 22%, respectively (P < 0.0001). Survival for "unresectable" patients treated with RFA + resection or RFA only was greater than chemotherapy only (P = 0.0017). Hepatic resection is the treatment of choice for colorectal liver metastases. RFA alone or in combination with resection for unresectable patients does not provide survival comparable to resection, and provides survival only slightly superior to nonsurgical treatment.