Acute pancreatitis is an inflammation of the glandular parenchyma of the retroperitoneal organ that leads to injury with or without subsequent destruction of the pancreatic acini. This inflammatory process can either result in a self-limited disease or involve life-threatening multiorgan complications. Chronic pancreatitis consists of endocrine and exocrine gland dysfunction that develops secondary to progressive inflammation and chronic fibrosis of the pancreatic acini with permanent structural damage. Recurrent attacks of acute pancreatitis can result in chronic pancreatitis; acute and chronic pancreatitis are different diseases with separate morphologic patterns. Acute pancreatitis has an increasing incidence but a decreasing mortality.