The authors assess the efficacy of CT of the pancreas in a series of 151 patients with suspected pancreatic carcinoma. CT diagnoses were divided into four categories based on the original interpretation: "mass" or carcinoma (53 scans); normal pancreas (68 scans); normal pancreas, but another pathologic process was discovered on the CT scan (20 scans); and unsatisfactory or indeterminate examinations (10 scans). In more than 50% of the erroneous diagnoses of pancreatic carcinoma, the mass lesion seen on CT was found at surgery or angiography to be adjacent to, not arising from, the pancreas. False-positive interpretation can be avoided by improved equipment and technique and the accumulation of interpreter experience.