There is strong evidence that induced pancreatic adenomas and carcinomas derive from ductal and ductular cells in the pancreas. We base our beliefs on our knowledge of the embryology and histology of the pancreas in Syrian golden hamsters, along with the sequential alterations that occur during exocrine pancreatic tumor formation. This concept also has been supported by much experimental evidence, including autoradiographic, immunologic and in vitro studies. We also present other viewpoints on the origin of pancreatic cancer histogenesis and outline certain areas of disagreement. We report the development of acinar cell lesions under certain experimental dietary conditions in hamsters (the lesions resemble those commonly seen in the rat pancreatic tumor model) and the nature of these lesions.