Based primarily on our experience, we review current problems on etiology, pathogenesis, classification, diagnosis, and treatment of chronic pancreatitis. Much of the confusion and difficulty associated with chronic pancreatitis originates from the relative inaccessibility of this organ. A lack of specific and sensitive markers that are suitable for the follow-up of a long natural course of chronic pancreatitis also hinders our understanding of this disease. The resolution of the present imaging tests, even by the latest technology, is not good enough to detect early changes of the pancreas. In the past 10 years, several subgroups of patients with alcoholic and idiopathic pancreatitis have been identified based on the long-term follow-up study. Pain disappeared spontaneously in many patients during the course of the disease, but its mechanism is still poorly understood. Removal of pancreatic stones and protein plugs by chemical, endoscopic, or extracorporeal shock-wave therapy has been tried with some success, but their clinical values remain to be established. Attempts have been made to understand the etiology and pathogenesis of chronic pancreatitis at molecular levels. This approach, together with a prospective follow-up of patients, will improve our understanding on chronic pancreatitis.