More frequent use of the endoscope to remove gastric mucosal polyps has also led to better knowledge of the pathology of these polyps. Their classification is still a matter of debate, and hence, by way of introduction, the notions of hyperplastic, hyperplasiogenous and hyperplastic-adenomatous polyp, adenoma, borderline lesion protruded type, foveolar hyperplasia and cysts of the gastric glands are presented. The authors give preference to the WHO classification of 1977. Among 196 mucosal polyps examined between 1970 and 1982 84% were hyperplastic (hyperplasiogenous) polyps, 15.5% adenomas and there was a single specimen of hamartomatous polyp. One in every 6 adenomas showed malignant changes and 5 of the 165 hyperplastic polyps were associated with gastric carcinoma. Problems of diagnosis, classification and prognosis are briefly discussed.