On necropsy of a 24 months age Dutch female rabbit the uterine horns seems enlarged with a nodular appearance. On the cut surface of the uterus as well as heart wall, white firm masses with a cauliflower- like surface was observed. No other important gross lesions were found in other organs. In histopathological examination of the uterus typical microscopic changes were those of adenocarcinoma. No metastases except in heart wall were found in lung, spleen and liver. In the heart most of the myocardial cells were replaced by tumor masses and the reminder were degenerative. Microscopic features of the metastases in the heart wall were similar to the primary neoplasm.