Multifocal gastric carcinoma arising from hyperplastic and adenomatous polyps. This paper is a presentation of the unusual case of a 61-yr-old woman operated on for multiple gastric cancers. Two of the cancers were found in the hyperplastic polyps and one in the adenoma. Apart from cancers that arose from these polyps, there were four separate polypoid or flat gastric carcinomas and three other hyperplastic polyps with no signs of malignancy, in this case. The presentation is followed by a detailed discussion focusing on the possible development of carcinoma in gastric hyperplastic polyps in view of the data from the literature. 