Not all patients with liver metastases should be referred to the surgeon. Selection is necessary, based on the patient's general and hepatic condition, on the nature of the primary cancer and on the intra-hepatic spread of the metastases. At the moment, less than 1% of patients with metastatic liver are operated upon. In the absence of clinical or biochemical evidence of hepatic dysfunction, surgical specialists may consider operating patients under 75 with synchronous or metachronous metastases from colorectal cancer or endocrine tumours. If clinical and laboratory evaluation is favourable, the decision to operate and the type of partial hepatic resection selected depend on pre-operative investigations which are, successively: ultrasonography, computerized tomography, radioisotope scanning and possibly arteriography for endocrine tumours (not all these examinations are necessarily required). Other possible referrals are patients with liver metastases from non-colorectal or non-endocrine primary tumours of low evolutive potential, as evaluated by changes in levels of biological markers and by monthly morphological studies of metastatic tissue over 3 to 6 months. The major limiting factor in these patients is previous heavy chemotherapy which makes this type of surgery extremely hazardous. Recently published data justify primary surgical reduction of the tumour followed by systemic or regional chemotherapy at the end of the liver tissue regeneration period. In marker-dependent subjects the susceptibility to chemotherapy of the remaining malignant tissue can be evaluated by changes in marker levels if these were still above normal values after partial hepatectomy.