Although the nutritional approach, especially when delivered through a gastric or jejunal tube or in a central vein, is handled by the nutritional support team or a specialist in nutrition, it is the responsibility of the oncologist, who knows the natural history of the disease and the impact of the oncologic therapy, to identify the potential candidates for the nutritional support, to recommend the nutritional strategy and to integrate it within the oncologic program. If gastrointestinal function is preserved, the initial nutritional approach should be through oral supplementation, followed by tube feeding if previous attempts are unsuccessful or upper gastrointestinal tract is not accessible. Parenteral nutrition is the obligatory resort when patients are (sub)obstructed but it may also be a practical way to integrate an insufficient oral nutrient intake (so called "supplemental" parenteral nutrition). Depending on the patient's condition and the disease's stage, artificial nutrition may have a "permissive" role in patients receiving aggressive oncologic therapy or represent just a supportive treatment in patients likely to succumb from starvation sooner than from tumor progression.