The use of transvaginal sonography (TVS) in the management of infertility is gaining increasing popularity. The improved resolution and better tissue textural differentiation afforded by TVS makes this technique useful in monitoring ovarian follicular growth, ovulation, and corpus luteum formation, and in evaluating the normal anatomy of the uterus and the cervix and their cyclic response to ovarian steroids. Adnexal and cul-de-sac abnormalities related to infertility can also be identified. TVS-guided procedures can be accurately and safely performed; transvaginal follicular aspiration, gamete or embryo transfer to the Fallopian tube, and fetal reduction are just a few of the procedures recently introduced to reproductive medicine.