Vulvar or vaginal neoplasia was diagnosed in 99 dogs. The most common clinical sign was vulvar discharge or the sudden appearance of a protruding mass from the vulva. Most of the dogs were old (average age, 10.8 years) and sexually intact. Of the 99 tumors, 72 were benign, 17 were malignant, and 10 were transmissible venereal tumors. Except for the transmissible venereal tumors, most tumors were of smooth muscle or fibrous tissue origin (leiomyoma, fibroma, and leiomyosarcoma). In the dogs with benign tumors, surgical excision of the tumor combined with ovariohysterectomy was effective in preventing recurrence of disease.