Mild stimulation protocols have been implemented to be offered to subfertile patients who respond poorly to ovarian stimulation. We aimed to compare the efficacy of mild versus conventional gonadotropin-releasing hormone (GnRH)-agonist and antagonist protocols in poor responders undergoing in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycles. A total of 58 poorly-responding patients were divided into two groups: mild group (n=33), receiving clomiphene citrate 100 mg and 0.25 mg of cetrorelix with 150 IU of gonadotrophins daily; conventional group (n=25), undergoing the long GnRH-agonist or -antagonist protocols. The primary outcome was the number of cumulus oocyte complexes (COCs) retrieved. A lower number of COCs [median (range)=1 (0-4) vs. 3 (0-8.4), p<0.001] was retrieved in the mild stimulation compared to the conventional group. Secondary outcomes favored the conventional group, whereas live birth (9.1% vs. 12%), clinical pregnancy (12.1% vs. 20%) and miscarriage rate (40% vs. 40%) were similar in the two groups. Mild ovarian stimulation is inferior to conventional regimes when applied to poor responders undergoing IVF/ICSI, in terms of the numbers of retrieved COCs.