A case of vaginal fibrosarcoma in a 4-year-old pregnant (6th month) cow is described on the basis of clinical, macroscopic and microscopic findings. Tumor mass surgically excised from the vagina was nodular and firm, sized 40mm x 60mm. Histopathologically, neoplastic tissue originated from the mucosal connective tissue. Tumor cells showed highly proliferating pattern with cellular and nuclear pleomorphism (anisocytosis and anisokaryosis). In addition, some tissue parts were very well vascularized.  Excision of the tumor mass was easy and successful; with neither hemorrhage nor postoperative infection. At the 5^th post surgical month, no evidence of regrowth of any tumor tissue was found. This paper reports the first clinical investigation, surgical treatment and pathological description of a vaginal fibrosarcoma in Algeria.