To compare follicular fluid concentrations of IGF-I, IGF-II, IGFBP-3, inhibin-B, VEGF, and AMH in women undergoing controlled ovarian hyperstimulation with a long-luteal GnRH agonist protocol or multiple-dose GnRH antagonist protocol.A total of 80 cycles were included; long-luteal GnRH agonist group (n=40) and multiple dose GnRH antagonist group (n=40). All follicular fluid samples were obtained from mature follicles during oocyte retrieval. IGF-I and IGFBP-3 concentrations were measured by immunoradiometric assay. IGF-II, VEGF, AMH, and inhibin-B concentrations were measured by enzyme-linked immunosorbent assay.There were no significant differences in the concentrations of the studied follicular fluid markers, cycle parameters, and treatment outcomes between GnRH agonist and GnRH antagonist protocols.The long-luteal GnRH agonist protocol and multiple-dose GnRH antagonist protocol seem to have similar effects on the follicular microenvironment in women undergoing controlled ovarian hyperstimulation.