We present a case of fundic gland polyps (FGPs) containing high-grade dysplasia in a 68-year-old man. High-grade dysplasia, and even gastric adenocarcinoma, associated with FGPs have been described in patients with familial adenomatous polyposis (FAP) and attenuated familial adenomatous polyposis (AFAP) but never in non-FAP patients. Two colonoscopies in the past six years virtually rule out FAP and AFAP in our patient. Dysplasia in FGPs from non-FAP patients is extremely rare, and until now only cases of low-grade dysplasia have been described. The literature on dysplasia in FGPs is reviewed briefly. Additional immunohistochemical investigations in this case showed nuclear staining of beta-catenin, increased proliferation and apoptosis in the dysplastic areas of the FGPs. Our case suggests that the malignant potential of FGPs is not limited to FAP-associated FGPs.