Over recent years, the interest in the development of experimental models of colorectal liver metastases has increased due to the need for new adjuvant therapies to improve the treatment of both colorectal cancer and liver metastases. The induction of colon cancer by carcinogens in the rat with spontaneous liver metastases fairly closely mimicks the natural history of colon cancer but a low yield of both colonic cancer (less than 50%) and liver metastases (approx. 25%) is obtained after 6 months of latency. Direct intraportal injection of cells derived from a colon carcinoma cell line is the experimental model most often used. Although it bypasses the natural history of cancer this simple model produces up to 100% of liver metastases 6 weeks after injection of cells. These two models have been used for several studies of liver metastases concerning their morphology, their modulating factors and their vascularisation. They have been used to test new adjuvant therapies for colorectal cancer.