Round ligament of uterus leiomyoma is a rare, benign tumor of the vulva. Its incidence is not known exactly, and the mean age ranges from 13 to 70. Although clinical properties of benign and malignant diseases in the vulvar area are frequently similar, early diagnosis and treatment are essential. Local excision is recommended as definitive therapy. We present an 28-year-old female without any birth with a mass in anterior vaginal wall diagnosed as vulvar leiomyoma. In conclusion, a brief review of relevant literature emphasizes that leiomyomas are quite rare outside of the uterus but they might occur in any tissue or organ containing smooth muscle, spontaneously or parasitically after the spreading effect of an accident or surgical trauma. Clinicians should be alert especially for the diagnosis in a tissue with smooth muscle content.