Correct controlled ovarian stimulation is of paramount importance in assisted reproductive technologies. Therefore, analysis of the ovarian reserve of the patient is mandatory to tailor the best ovarian stimulation regimen. When the ovarian reserve is reduced, the induction of a multifollicular growth remains a challenge. Several factors could be associated with reduced ovarian response. However, reduced ovarian reserve either in older patients or in young patients represents the most frequent aetiological factor. Whatever is the aetiology, one of the main problems is how to predict a reduced ovarian response, and although several tests have been suggested, no very accurate predictive test is available. A variety of different stimulation protocols have been suggested but the lack of any large-scale, prospective, randomized, controlled trials of the different management strategies and the lack of a uniform definition of the population may result in comparisons of heterogeneous groups of patients, making it difficult to draw any definitive conclusions. Natural cycle IVF may represent an easy and cheap approach in the management of this group of patients. Although no controlled large prospective randomized studies are available to compare the natural IVF procedure with ovarian stimulation IVF in poor responder patients, the efficacy of natural cycle IVF is hampered by high cancellation rates mainly due to untimely LH surge. The use of gonadotrophin-releasing hormone antagonists in the late follicular phase, which reduces the premature LH rise rate, and the improvements in laboratory conditions and fertilization techniques, increase the embryo transfer rates, making this procedure more cost-effective.