The present study describes a family (mother and son) with Gardner's syndrome. Aside from the classical findings, gastric polyposis was found; histologically glandular cysts of the fundic mucosa were diagnosed. The occurrence of gastric polyps in Gardner's syndrome has recently been described with increasing frequency. These lesions have various histological aspects. A number of authors have noted several cases of Gardner's syndrome with glandular cysts of the fundic mucosa, but to our knowledge this is the first case of familial occurrence.