The majority of patients with colorectal liver metastases presents with unresectable disease. Without resection, the prognosis for these patients is extremely poor. The technical inability to completely remove all metastases while leaving at least 30% of remnant normal functioning liver parenchyma is nowadays regarded as the only absolute contraindication to resection. Chemotherapy regimens containing combinations of 5-fluorouracil, leucovorin, oxaliplatin and/or irinotecan can provide significant downstaging of liver disease enabling curative rescue resection and resulting in improved long-term survival. The addition of cetuximab and bevacizumab may result in higher resectability rates that may offer curative surgery in a larger amount of patients. In addition, different surgical techniques like portal vein embolization, two-stage hepatectomy and local ablation are available to achieve a resectable situation. Due to vascular exclusion and reconstruction techniques, tumoral involvement of the hepatic veins and inferior vena cava no longer limits the indication of resection. Overall, surgery should be performed as soon as liver metastases become resectable. Collaboration between oncologists and surgeons is essential to optimize individual therapeutic strategies.