In this case, a male Terrier dog, 14-year-old evaluated with a history of cardiac arrhythmias, coughing, rhinorrhagia and exercise intolerance for six mounths. The dog was died upon worsening of clinical signs. At necropsy, two masses of various sizes were observed in the heart-base region. Microscopically, cells from masses were atypic and polyhedral with eosinophilic-granular cytoplasm and basophilic nucleus with round to oval shape. The neoplastic cells were divided into lobules by connective tissue forming nests. In addition to these findings, metastasis to the left kidney was observed. Immunohistochemically, the tumor cells from both primary and metastatic tissues showed immunoreactivity to monoclonal mouse anti-neuron specific enolase antibody but were negative for cytokeratin, vimentin, chromogranin A, a smooth muscle actin and S-100. Based on the clinical, histological and immunohistochemical findings, malignant aortic body tumor with left kidney metastasis was diagnosed in the present case.