Predicting the course of an attack of acute pancreatitis still represents a challenge for the physicians. Some early interventions such as endoscopic retrograde cholangiopancreatography and sphincterotomy, admission to the intensive care unit, enteral feeding, and prophylactic antibiotics have been proven to decrease morbidity and mortality in patients of high-risk groups. However, acute pancreatitis has a potential of morbidity and mortality, and therefore early diagnosis and objective assessment of severity of the disease is fundamental. To date, many different prognostic scores have been applied to the initial management of acute pancreatitis for the evaluation of the severity of disease. However, each of the scoring systems has advantages and disadvantages. In this paper, we tried to summarize the prognostic scoring systems and their performances in assessing severity and prognosis of acute pancreatitis.