Background: Acute pancreatitis is pancreatic inflammation that often associated with increase of symptoms such as epigastric pain, nausea and vomiting, diarrhea, loss of appetite, fever, chills, shock and hemodynamic complications. Early nutritional support has an important role in preventing serious complications, malnutrition and promote the recovery of patients. The aim of this study was to compare early initiation of enteral nutrition versus late enteral nutrition and total parenteral nutrition.

Materials and Methods: This study is a review study, using key words are enteral nutrition, early enteral nutrition, parenteral nutrition, acute pancreatitis and clinical guidelines. Information compiles by use of PubMed, CINAHL, Google, Ovid, Google scholar, Science Direct databases between 2000-2015 years. For this article, were used randomized clinical studies and comparative studies in which mortality rates, complications and length of hospital stay were reported.

Results: Now, early enteral nutrition is preferred to delay enteral nutrition and total parenteral nutrition. Because this method is more efficient and less expensive, mortality and morbidity. Complications such as infection, organ failure and length of hospital stay were significantly less and blood sugar is better controlled.

Conclusion: Studies and guidelines insist on early enteral nutrition and if there is no constraint for the patient, should be started as soon as possible. It is suggested that in Iran, as well as research in this regard.