A 7-year-old intact female Golden Retriever was presented for examination. The dog had large irregular subcutaneous masses in the abdomen which were ruptured or encapsulated. Those were removed surgically. Histopathologically, the masses consisted of spindle cells that often formed distinct whorls around a central capillary. Immuno-histochemical analysis revealed that the neoplastic cells were strong diffuse cyto-plasmic immunolabelling for vimentin and focal immunoreactivity for smooth muscle actin, whereas not immunoreactive for cytokeratin, desmin, von Willebrand factor, glial fibrillary acidic protein, or S-100. The neoplastic cells ultrastructurally had processes attached by desmosome-like structures, swollen mitochondria and dilated rough endoplasmic reticulum. Based on the above results, this case was diagnosed as a canine hemangiopericytoma in the abdominal subcutis of a Golden Retriever.