Numerous intranuclear inclusion bodies in enterocytes were detected exclusively in the ileum of two nine-day piglets coming from a litter infected with diarrhea. The inclusion bodies were homogeneous in hematoxylin and eosine (HE), their staining was not clear enough, was amphophilic and they filled nearly the whole nucleus. They were eosinophil less often and had a halo on the periphery. Their staining was clearly orange-red in Feulgen's nuclear reaction after re-staining with G orange and bright green. Intranuclear inclusions were located exclusively on shortened villi and pseudovilli of ileum above the follicles of activated Peyer's patches. The findings of intranuclear inclusions in ileum demonstrate adenovirus enteral infections in suckling piglets.