Objective: to propose a clinical practice guideline of nutrition for patients with severe acute pancreatitis derived from the best available evidence. Design: systematic review and clinical practice guideline. Setting: critically ill patients at the intensive care unit. Patients: with severe acute pancreatitis. Intervention: enteral or parenteral nutrition. Glutamine or no glutamine. Arginine or no arginine. Omega 3 fatty acid or control. Outcome: mortality, pulmonary, catheter associated or pancreatic infection, sepsis, ICU or hospital length of stay. Methodology: medical database online search. Results: 765 initial references were filtered with key words and 69 remained. 5 other articles in Spanish were considered pertinent. Conclusions: patients with severe acute pancreatitis benefit from nutritional support, and isocaloric early enteral route is of choice during the first 3 days. Nutritional intervention could be a determinant in lowering the high morbidity and mortality rates linked with this entity, but well designed trials that elucidate the true individual effect of each constituent are scarce.