The authors examine the value of different imaging techniques (CT, MRI) in the diagnosis of the involvement of the mesenteric-portal vessels in the pancreatic cancer. In 20 jaundiced patients, they obtained in all cases a correct diagnosis about the etiology of the jaundice. The correspondence of the preoperative imaging study with the involvement of the mesenteric-portal vessels was respectively 73% for the CT and 78% for the MRI. In all cases, the intra-operative echography allowed a correct diagnosis of the vascular involvement.