Backround: Recently, the Stop GnRH agonist protocol has been used successfully in poor responder patients , those with poor embryos quality and those with elevated peak serum progesterone levels. The aim of the present study was to evaluate, whether GnRH-agonist trigger in patients undergoing the Stop protocol combined , will result in an optimal response/trigger, as reflected by post trigger LH >15 mIU/mL Methods: A retrospective cohort study. All consecutive women admitted to our IVF unit from February 2020 through November 2020 who reached the ovum pick-up stage. Patients triggered with GnRH-ag alone, or combined with hCG for final oocyte maturation were included in the study. LH levels were measured 12 hours post trigger.Results: Five out of the 32 patients (15.6%) demonstrated suboptimal response as reflected by LH levels <15 IU/L 12 hrs post GnRH-agonist trigger. Moreover, while no differences were observed in oocytes recovery rate, maturity or embryos quality between the different study groups, those achieving a suboptimal response to the GnRH-agonist trigger (post trigger LH <15 mIU/mL) demonstrated significantly higher number of follicles and peak estradiol levels at the day of trigger.Conclusions: The Stop GnRH-agonist combined with GnRH-antagonist protocol, enables the substitution of HCG with GnRH-ag for final oocyte maturation. However, caution should be taken in high responders, where the dual trigger with small doses of hCG (1000-1500IU) should be considered, aiming to avoid suboptimal response (post trigger LH levels <15IU/L).