Since its development, endoscopic retrograde cholangiopancreatography (ERCP) has been playing a major role in the diagnosis of pancreatic diseases. The recent development of magnetic resonance cholangiopancreatography has accelerated the shift in the role of ERCP toward more therapy-oriented applications. In the diagnosis and treatment of curable pancreatic cancer, however, ERCP remains the mainstay of imaging modalities. ERCP is not simply a method with which to obtain x-ray images of the pancreatic duct. Collection of pure pancreatic juice, transpapillary biopsy/brush cytology of the pancreatic duct, intraductal ultrasonography, and peroral pancreatoscopy are all performed based on the ERCP technique. Endoscopic ultrasonography (EUS) has a high spatial resolution and provides tomographic images of the pancreas and its neighboring organs. EUS is now widely used in evaluation of the local extent of pancreatic cancer and the differential diagnosis of cystic lesions of the pancreas. EUS-guided fine needle aspiration biopsy/cytology is performed to obtain a histologic diagnosis before beginning chemotherapy. Although the number of pancreatic cancer patients who are candidates for surgery is limited at present, there is an increasing need for ERCP-based techniques in both the diagnosis and treatment of pancreatic neoplasms.