As there are only few reports on the occurrence of carcinoma in hyperplasiogenic polyps there is at present no general agreement concerning the malignant potency of these polyps in the stomach. In this paper we review the literature and present the unusual case of a patient who developed carcinoma in a hyperplasiogenic polyp with a diameter of 15 x 5 mm. Whereas in nearly all the reported cases cancer developed in polyps with a diameter greater than 2 cm our findings demonstrate that even in smaller polyps malignant changes have to be suspected.