Radial endoscopic ultrasonography (EUS) is used in pancreatic pathology for diagnosing such diseases as: chronic pancreatitis, cancer of the pancreas, neuroendocrine tumors, and the non-inflammatory cyst lesions of the pancreas. For diagnosing chronic pancreatitis, the use of more than four criteria of endoscopic diagnosis offers a high diagnostic accuracy. In the case of tumors of the pancreas, EUS detects small-size tumors, having a major diagnostic value in the preoperative staging and in assessing the tumor resectability. EUS can best identify insulinoma, while for the differential diagnosis of cystic neoplastic lesions data provided by radial EUS are not sufficient. In this respect, intracyst fluid analysis is required to identify malignant lesions or those having malignancy potential.