Malnutrition in cancer patients is associated with a poor prognosis, weight loss being an important predictor of mortality. The cancer and its treatment have a great impact on nutritional status, so by applying nutritional therapy can improve quality of life, prognosis and functional status. The application of standards of practice this therapy in cancer patients can reduce variability of interventions and promote efficient, safe and quality use. Being the hospital pharmacist as part of the nutritional support team a key in optimizing nutrition therapy through four strategic partner roles: clinical, technical, operational and manager.