Acute pancreatitis is a disease with varying severity. Patients with the mild form do not require nutritional support because oral intake is resumed rapidly. Studies on nutritional support in acute pancreatitis have included patients with both mild and severe disease. In this heterogeneous group, total parenteral nutrition did not improve outcome compared with no nutrition at all. This is caused in part by an increase in septic complications during total parenteral nutrition. Likewise, no benefit from enteral nutrition was observed compared with no nutrition, probably because the group was heterogeneous or because nutritional goals were not achieved. Patients with severe acute pancreatitis become profoundly catabolic. This group undoubtedly requires nutritional support to treat undernutrition. The limited available data indicate that enteral nutrition, if well tolerated, is superior to parenteral nutrition for patients with severe acute pancreatitis. Based on current knowledge, a combination of early total parenteral nutrition and enteral nutrition is advisable as soon as enteral nutrition is tolerated. Monitoring of gut function is crucial in this situation.