In patients with primary colorectal cancer the development of liver metastases has traditionally been equated with imminent demise. This metastatic event is remarkably common; indeed, liver metastases are present in some 25 per cent of patients at the time of initial colorectal resection and over 50 per cent of patients will eventually develop them. Some 90 per cent of patients who die from colorectal cancer have liver metastases. There are few cancers in which the metastatic pattern has such a high degree of predictability. Information from past and present clinical studies should, therefore, provide a basis for logical approaches to prevention and treatment.