Pure pancreatic juice has been collected from 61 patients at the time of endoscopic retrograde cholangio-pancreatography (ERCP) for the purpose of cytodiagnosis. The ERCP and cytological findings are discussed. Pure pancreatic juice cytology may help in the interpretation of the pancreatogram in both pancreatitis and pancreatic carcinoma. In patients with pancreatic carcinoma, ERCP alone was diagnostic in 65%, cytology alone in 54%. By combining these two approaches, a diagnostic result was obtained in 92% of patients.