AbstractThermoablation is a local therapy that is effective in in situ destruction of colorectal liver metastasis while preserving surrounding normal liver tissue. It is less invasive compared to surgery, easy to use, and can be repeated. The therapy provides local control of unresectable disease and is an alternative therapy for small resectable lesions in patients with insufficient hepatic reserve after resection or coexistent comorbid conditions. It can artificially increase the resection margin thus increasing the number of patient candidate for resection. When used in conjunction with liver resection it clears the liver of multiple lesions that are surgically inaccessible or unresectable. Main limitations of the treatment are local recurrence of the disease, treatment‐related complications, and questionable impact on patient. Outcome of therapy can be improved when used as part of multimodality treatment. J. Surg. Oncol. 2010; 101:699‐705. © 2010 Wiley‐Liss, Inc.