Staging of acute pancreatitis is important for selection of patients for clinical trials, comparison of results between centers, and the early identification of patients who may benefit from therapeutic intervention or transfer to a specialist unit. The APACHE-II score and other multiple-factor scoring systems are widely used for the first two indications, and of these, the APACHE-II score provides the best accuracy at an early stage in the course of the illness. Presently, however, no system provides sufficient predictive power to facilitate clinical decision making. At a time of increasing pressure to involve specialist units at an early stage in the management of these complex patients, a pressing need to identify a system for accurate early staging of acute pancreatitis remains.