The occurrence of hemangiosarcoma, with characteristics of high-aggression is reported in the skin of the parietal region in female canine Golden Retriever, 8 months of age. The history has showed nodular and bleeding mass, followed by mild pruritus, which was pressured by the owner to remove the content, supposedly, the fly larva (cloth). In the open wound a myiasis has developed and that led to an appointment. The cleaning of the wound was done at the clinic. The infective larvae were removed. Treatment with penicillin and enrofloxacin was prescribed. The inflammatory process has been reduced allowing more security for the removal of the mass, which had a fusiform aspect with approximately 5 x 2 centimeters in the wider portion. According to a safety margin of 5 centimeters, a removal with electrocautery was performed. In the postoperative healing ointment was used on allantoin base. A sample was sent to the department of Animals Pathology of Veterinary Department--UFPEL, where was identified an hemangiosarcoma with high potential markers of malignancy, such as large areas of high cell density, high mitotic and apoptosis index. Before the removal of the suture, bleeding was found in the wound, suggesting dehiscence; with local exam it was possible to identify recurrence of the tumor. A new surgical approach was performed with dissection of the mass, reaching the subcutaneous tissue and some subjacent muscle tissue. In this approach an area of about 7x4 centimeters was taken. The skin hemangiosarcoma can be unique and has no certain cause, but the solar incidence on lightly pigmented skin may be implied; the skin is the third incident place in canines (after the spleen and the heart). The average age of affected dogs is 10 years, and it seems to be a greater predisposition for females. In a retrospective study of 268 hemangiosarcomas, 7.8 % occurred in the head. The tumor may be dermal or subcutaneous, characterized by the proliferation of fusiform, polygonal or ovoid cells, that form vascular canals; the cells have large nucleus formed by aggregated chromatin. The Golden Retriever breed is among the predisposed. The histological characteristics establish the diagnosis of hemangiosarcoma highlighting the occurrence not so common in the head of young dogs.