Lymphangiosarcoma was described in a 2-year-old male Miniature Poodle. A 5 cm by 3 cm slightly elevated tan ventral abdominal mass was surgically removed with a wide margin and submitted for diagnosis. The mass has being grown rapidly during the last six months. On histopathology, the mass was composed of anastomosing channels or empty spaces which were free of red blood cells and lined by flat to plump pleomorphic neoplastic cells. The neoplastic channels or spaces were invasive into the surrounding fat and muscle tissues. Mild perivascular lymphocytic infiltration was also noted. Immunohistochemically, the neoplastic cells were positive to vimentin and Factor VIII. Based on histopathology and immunohistochemistry, the tumor was diagnosed as lymphangiosarcoma. Recurrence or metastasis was not noted so far after surgery.