A rare and interesting alteration--hyperplasia of Brunner's glands--is reported. In 18 cases hyperplasia of Brunner's glands were verified by endoscopy and histology as well. Frequency of occurance, clinical characteristics, X-ray symptoms of the hyperplasia of the Brunner's glands and the radiological methods of its diagnosis are described. Importance of the aimed X-ray film, carried out by Spot-filmkamera and of graded compression is emphasized. Differential diagnosis between polypoid hypertrophic duodenitis and hyperplasia of Brunner's glands are discussed in detail.