The technique of transvaginal ultrasonographic aspiration was repeatedly used in a temporarily infertile mare for the evacuation of one anovulatory follicle occurring during two breeding seasons. The mare reassumed normal ovarian activity immediately after each aspiration with an ovulation detected on the 5(th) and 14(th) day, respectively. The mare conceived 9 weeks after the first aspiration to an oocyte ovulated from che ovary opposite the one aspirated. After the second aspiration, che mare did nor conceive, probably because of law sperm quality. It can be concluded that transvaginal ultrasonographic aspiration provided a rapid and elegant met hod for the removal of anovulatory follicles, allowing immediate return to normal ovarian cyclicity. The differential diagnoses of enlarged follicular structures are disiscussed.