To describe three clinical cases involving patients at high risk of severe ovarian hyperstimulation syndrome (OHSS) during IVF stimulation. Description of clinical management of IVF cycles and outcomes in patients at risk of developing OHSS. Reproductive medicine unit, private hospital. Three infertile patients undergoing stimulation for IVF/intracytoplasmic sperm injection presenting high risk of OHSS. IVF patients treated under long protocol presenting high risk of OHSS had their cycles rescued by withdrawing the agonist and replacing it with an antagonist and triggering ovulation with an agonist bolus. OHSS symptoms, pregnancy. None of the three patients developed OHSS. One patient got pregnant after fresh embryo transfer, one patient got pregnant after frozen embryo transfer, and one patient had no oocytes retrieved despite the detection of LH in urine after the GnRH bolus. When a patient undergoing an IVF cycle with long protocol is at high risk of severe OHSS, rescuing the cycle by withdrawing the agonist and replacing it with an antagonist and triggering ovulation with an agonist bolus could be considered without jeopardizing the safety of the patient while retaining the opportunity for success of the cycle. Further broader studies are needed.