Surgery is the best treatment modality for colorectal liver metastases. When initially unresectable, hepatic resection of metastases after downstaging by chemotherapy can provide a hope of long-term survival similar to that of primarily resected patients. Definitions of resectability have evolved with the emerging principle that if metastases can be completely resected regardless of their size and number,resection should be performed as the sole mean of achieving long-term survival. Specific surgical techniques can be combined to improve resectability. If the tumor is considered unresectable, recent developments make possible to render some tumors surgically resectable. Depending on the tumor size, number and location, neoadjuvant treatments, mainly chemotherapy, can be used, followed by resection. Resection may be contraindicated if the residual volume of liver is inadequate to avoid liver failure. This may be changed either by PVE or two-stage hepatectomy, both of which use the natural regenerative capacity of the liver. Local destructive therapies such as cryosurgery and radio-frequency can also be used in conjunction with resection for patients in whom all metastases are not surgically resectable. The present use of these ablative techniques is improving the percentages of unresectable patients considered for surgery. All of the above-described methods can be combined to achieve a surgical strategy that is as curative as possible, increasing the number of patients primarily unresectable, with a long-term survival hope similar to that of primarily resectable patients. To achieve this objective, a close collaboration between oncologists, radiologists, and surgeons is mandatory, with routine re-evaluation of patients for an adequate timing of each treatment.