From 314 patients with coeliac disease, 20 patients were found to have developed a lymphoma. The incidence of lymphoma was much greater in the 6th, 7th and 8th decades of life than in the previous two decades. In 12 patients, the lymphoma was diagnosed within 4 years of the diagnosis of their coeliac disease and there were significantly more of these lymphomas appearing in coeliacs diagnosed between 51 and 80 years, who made up 23% of the series, than in those diagnosed between 21 and 50 years. We conclude that lymphoma is particularly a complication of older coeliacs and that coeliacs newly diagnosed at more than 50 years of age should be more closely followed up for they have a 1 in 10 chance of harbouring a lymphoma.