The long-term consequences of screening for celiac disease in diabetic children are not known. Routine screening is not practiced in our pediatric diabetic population. This study of the incidence of the most severe and specific long-term complication of untreated celiac disease, i.e., enteropathy-associated T-cell lymphoma (EATCL) and its association with diabetes, is done in order to justify our strategy not to practice routine screening. In the first phase of this study, a questionnaire was sent to all Swiss pathologists. The second phase consisted of a search in the cancer registry of the canton of Zurich. The incidence of EATCL in the general population of a Swiss region and the theoretical risk for a diabetic patient to develop this type of lymphoma were calculated. Ten cases of EATCL were found. Five had a long history of malabsorption, three of them since childhood. The mean age of the patients was 61.9 yr. None suffered from diabetes mellitus. The incidence of EATCL was 0.07/100,000 inhabitants/year. The expected risk for EATCL in patients with type 1 diabetes is 12.4/100,000 diabetic patients over a period of 60 yr. The data suggest that the risk for EATCL is small in diabetic patients. Therefore, we restrict the investigation for celiac disease to patients with typical and atypical symptoms, but do not perform routine screening.