Performance of intra-uterine insemination (IIU) is generally advocated as a first line therapy for infertility related to cercical hostility, male factor, unexplained infertility or mild endometriosis. IIU are usually performed following stimulation of ovulation, even in absence of anovulation. However the rationale for such a systematic ovulation induction is still questionable. Indeed, while an overall assessment of ovarian stimulation tends to conclude to a beneficial effect of these treatments in unexplained or some male infertility, it is clear that no definitive conclusion can be drawn. Indeed, the methodology in many published series is mostly inadequate, data are usually not analysed according to the type of infertility or to the female hormonal features. Finally, adverse effects are imperfectly descripted. A more accurate analysis of these data in relation to the number of recruited follicles definitively shows that, if a bifollicular development is associated with a significant increase in the pregnancy rates, there is no advantage to stimulate further the ovary. Indeed, surpassing the recruitment of two follicles would lead to dramatically increase the risk of OHSS and multiple pregnancies. Thus, further investigations including prospective, randomized studies are needed to better define what should be the most adequate regimen of ovulation induction. Specifically, tailoring the rate of multifollicular development according to the duration, the type of infertility (etiology; primary or secondary; female age) would prove to be a safer approach for getting pregnancy as well as avoiding adverse effects. Such a policy remains to be determined in the light of further clinical studies conducted in the more appropriate manner.