Among 192 cases of chronic pancreatitis, 51 (27%) were classifed as idiopathic after exclusion of all known aetiological factors. The age distribution of idiopathic chronic pancreatitis suggests that there are two separate entities, a "senile" (n = 38) (ISCP) and a "juvenile" form (n = 13) (IJCP). IJCP seems to represent a new nosological entity characterized by a low mean age at onset (25.6 years), a preponderance of males (n = 12), typical recurrent episodes of pancreatitis (n = 13), and a very high incidence of calcifications (n = 10). The course of IJCP seems to be rather benign but protracted. Despite lacking direct evidence, IJCP seems to be due to a genetic factor. The postulated causes of IJCP and ISCP may be identical with the primary factors which are considered to be responsible in combination with high alcohol intake, for the development of alcohol-induced chronic pancreatitis.