The existing histologic classifications of the pancreatic neoplasms were critically analyzed, and a revised classification was applied to 181 cases of primary neoplasms of the pancreas and its validity was examined. In addition, the results were compared with data from other countries for its relevance. Of the 181 cases, the epithelial tumors comprised 93.4%, islet cell tumors 11%, and the remaining one (0.5%) was of mixed exocrine-endocrine tumor. Of the exocrine tumors 9 cases (5.3%) were benign and the remaining 160 cases (94.7%) malignant. The ductal (ductular) cell origin comprised 122 cases (76.3%) of the all malignant exocrine tumors, being followed by 3 cases of acinar cell origin, and 13 cases (8.1%) of uncertain histogenesis. Most carcinomas were prevalent in the sixth and seventh decades af life, except for pancreaticoblastoma in the first decade and papillary cystic tumors in the second and third decades, respectively. As for ductal adenocarcinoma, male to female ratio was 2. 4:1, but islet cell tumor, papillary systic tumor and mucinous cystic tumor were absolutely prevalent in female. Ductal adenocarcinomas were located in the head portion 3.4 times frequent than in the body and tail portions. However, most mucinous cystic tumors and islet cell adenomas occurred in the body-tail portion. While the median size of ductal adenocarcinomas in the head and body-tail portions were same (5. 0 cm), the poorly differentiated tumors such as microadenocarcinomas, giant cell carcinomas and undifferentiated carcinomas were greater than 10 cm at the time of surgery. There was no significant difference of relative incidence in each histopathologic subtype except papillary cystic tumor which was more prevalent in Korea.