A common problem in cancer patients is a significant degree of malnutrition which disturbs and the accomplishment of surgery, chemotherapy and radiotherapy. Most patients with advanced cancer who should be treated with intensive chemotherapy are unable to ingest, digest or absorb sufficiently quantities of food and many antineoplastic agents affect the function of the alimentary tract. Therefore, total parenteral nutrition is a suitable method of nutritional support in these patients. The intravenous administration of nutrients can improve and maintain not only the nutritional status, but also the cell-mediated immunity of patients, and an effective or large doses of agents can be given as a result of increased tolerance. These effects are expected to enhance the potential of tumor response to chemotherapy. At the present time, only a few trials such as pulse TPN and amino acid imbalance therapy have been tried, but a specific nutritional regimen based on the altered metabolism in tumor and host should be developed in future.