A case of multiple primary tumors observed in the heart base and in the lung of a 7-year-old intact female, flat-coated retriever was reported. Morphological differences between both tumors and detailed immunohistochemical study revealed that the cardiac neoplasm was as a malignant aortic body tumor and the lung tumor was a pulmonary histiocytic sarcoma. The occurrence of aortic body tumor with other primary neoplasms has been previously reported in animals suggesting that this might be a common presentation in dogs.