Abstract Background: The introduction of gonadotropin releasing hormone (GnRH) agonist trigger for final maturation of oocytes in GnRH antagonist stimulated intra-cytoplasmic sperm injection (ICSI) cycles is widely used nowadays as it plays a major role in reducing ovarian hyper stimulation (OHSS) development in high responder patients e.g. polycystic ovary syndrome (PCOS). Polycystic ovary is one of the major causes of ovulatory dysfunction with an ICSI considered a suitable treatment modality in those patients with a high risk of multiple pregnancies and OHSS. Aim: The aim of this study is to compare ICSI outcome between GnRH agonist and hCG trigger in PCOS women stimulated by GnRH antagonist protocol. Materials and Methods: Forty one PCOS females were included. All were stimulated with GnRH antagonist protocol. When the total number and size of the developing follicles were accepted, oocyte maturation was triggered and they were divided in to two groups according to the type of the trigger: hCG trigger (n=18) and GnRH agonist (n=23). Following oocytes retrieval, microscopic assessment of oocytes maturity and embryos quality was done followed by calculation of pregnancy rate with a comparison of the results between both groups. Results: females whom their oocytes' maturation was triggered by GnRH agonist exhibited no significant difference regarding the total number of retrieved oocytes, oocytes' maturation rate and total number of good quality embryos in comparison with hCG-triggered at a p-value more than 0.05. While pregnancy rate in GnRH agonist was significantly less 22.72% vs 28.57% in hCG-triggered females, pvalue=0.01. Conclusion: Triggering with GnRH agonist had a comparable ICSI outcome to hCG inform of oocytes and embryos quality. The exception is pregnancy rate which is significantly lower with GnRH agonist which indicates that GnRH agonist might have unfavorable effect on endometrial receptivity lowering implantation rate.