Objectives. We compare the classic tomographic criteria of Balthazar and the index of severity as a predictive factor for the development of complications and length of hospital stay. Material and method. Retrospective study of 61 patients with clinical diagnostic of acute pancreatitis to whom an abdominal CT was made, with an intravenous bolus injection of contrast material. These explorations were analyzed with the Balthazar criteria, pancreatic degree of necrosis and the index of severity of the CT. Later, we made a correlation with the appearance of complications and the hospital days. Result. The result was similar to other studies in the prediction of complications and length of hospital stay, but with less average days in our series and without mortality. Conclusión. We concluded that the pancreatic factor of necrosis and the index of severity in the tomographic study improve the valuation foretells of the acute pancreatitis.