One hundred and ten patients were seen in the Department of Radiation Therapy at Thomas Jefferson University Hospital for pancreatic tumours between January 1975 and June 1980. Twelve patients had previously been treated for a non-pancreatic malignancy. Pancreatic biopsies were performed in nine patients and were interpreted as pancreatic carcinoma. When the previous pathological material was compared to the pancreatic biopsy, the diagnosis was changed in five of the 12 patients to recurrent non-pancreatic malignancy. We emphasise the importance of the distinction between primary pancreatic malignancy and metastatic disease in the pancreas.