We described the pathological findings of an abortion associated with Yersinia enterocolitica infection in an ewe. A late-gestation aborted ovine fetus and placenta were submitted for necropsy. Pathologic changes were restricted to the chorioallantois. Grossly, cotyledons and intercodilenary regions had areas of mild red discoloration, and cotyledons were covered with a small amount of fibrin. Histological lesions consisted of multifocal, severe necrotizing and fibrinosuppurative placentitis with fibrinoid vasculitis and mineralization. Bacterial culture of lung, abomasum, and placenta samples yielded pure growth of Y. enterocolitica. This report described the first case of infection by Yersinia enterocolitica causing ovine abortion in Brazil.