The carcinogenic mechanism of hepatobiliary and pancreatic tumors is still poorly understood, making the development of rational treatment strategies difficult. The Syrian hamster is a unique animal for studying these neoplasms because the anatomical structure of its hepatobiliary and pancreatic duct system is similar to that of humans. The tumors induced in the liver, biliary tract, and pancreas of hamsters with nitrosamines closely resemble those of humans and are ideal for investigating carcinogenic mechanisms. For the first time in book form, methods for the successful induction of hepatobiliary and pancreatic tumors in hamsters are explained, as are the surgical techniques for preparing animal models, the histopathological characteristics of the induced tumors, and chemoprevention. The hamster models of in vivo and in vitro tumorigenesis presented here will be a source of useful knowledge for basic researchers as well as for clinicians involved in the care of patients with hepatobiliary and pancreatic malignancies.