Computerized axial tomography (CT scan) of the abdomen is a sensitive method for examining the pancreas. Its sensitivity, however, may lead to the discovery of small mass lesions which do not represent neoplastic or inflammatory lesions. We describe our experience with 21 patients in whom mass lesions seen by CT scan were proven by endoscopic retrograde pancreatography (ERCP) to represent anomalies of the pancreatic duct. We call such lesions “pseudomasses.” Our findings support the need for opacification of the pancreatic duct system to rule out lesions arising from the duct whenever lesions of the pancreas are suspected on CT scan.