Some pertinent problems related to the long-term course of chronic pancreatitis are reviewed like progression and nonprogression of the disease, etiology and outcome, the different postulated pain mechanisms and the relationship of acute and chronic pancreatitis. Chronic pancreatitis is clinically a nonhomogeneous entity but some typical clinical patterns can be related to morphologic (histopathologic) and functional changes in the evolution from early to late stages. Clinical and histologic evidence is discussed, which suggests a close relationship between alcoholic acute and chronic pancreatitis.