Primary hepatocellular carcinomas are rare in dogs. A 12-year-old 5.4 kg female Poodle was referred to the Veterinary Medical Teaching Hospital with abdominal distension and mild anorexia. In this case, an extensive soft tissue mass was clearly palpable in the upper abdomen and radiography revealed a spherical mass of soft tissue density in the abdomen but its origin was not clear. In following an exploratory laparotomy, a partial hepatectomy was performed. Surgical complications were minimal. The survival time was seven months before dyspnea lead to a sudden and rapid decline.