Acute pancreatitis, a broad spectrum pathology, has a variable incidence, closely related to the geographic differences in its most frequent etiologies. Its pathogenesis remains to be cleared, with several proposed mechanisms. Pancreatitis' diagnosis, severity evaluation and the use of imagiologic and endoscopic auxiliary exams must be based in scientifically settled criteria. Treatment depends, mostly, on the episode's severity, but is mainly supportive. Pancreatitis' complications are responsible for the lethal cases and their classification as early, intermediate and late has practical utility. Based on a literature review of the pathology, including reference books and computer data bases, a systematized approach algorithm is proposed.