Acute pancreatitis is not the cause but may be a complication of chronic pancreatitis. Different forms of chronic pancreatitis are described. The most frequent type in all climates, chronic calcifying pancreatitis, has different causes but similar pathological changes. It is a lithiasis in which a new family of molecules. PSP, a calcium stabilizer, plays a dominant role. Studies of chronic pancreatitis have now reached the stage of molecular biochemistry.