The therapy of anovulatory infertility is not meant to obtain a pregnancy at any cost, but to restore an ovulation as physiological as possible. This involves the use of drugs and therapeutical protocols to obtain monofollicular cycles. Monofollicularity reduces the two main risks of induction of ovulation: ovarian hyperstimulation syndrome and multiple pregnancy. The aim of this study is a review of the Literature on ovulation induction and a comparison with the data of our Sterility Service. The importance of the question will be examined together with the most used ovulation induction drugs: clomiphene citrate, gonadotrophins and pulsatile GnRH. The parameters considered are: the number of follicles, single or multiple pregnancies and ovarian hyperstimulation. After a review about ovarian stimulation, the results of our Sterility Service are presented: 364 cycles of ovulation induction with clomiphene citrate, low-dose gonadotrophins or pulsatile GnRH were monitored; monofollicularity was obtained in 58,48% of ovulatory cycles. Differences between drugs will be described in the text. The therapy of anovulatory infertility aims to restore a physiological ovulation and to obtain a single pregnancy, not a pregnancy at any cost.