Phytoestrogens are a group of naturally occurring, plant and food-based compounds that have structural similarities to endogenous estrogens (e.g., 17beta-estradiol), synthetic estrogens (e.g., diethylstilbestrol), and even antiestrogens (e.g., tamoxifen).They can also bind to estrogen receptors and produce estrogen-specific gene products.Accordingly, these chemicals have the capacity to influence developmental trajectories in young females such as time to sexual maturity and affect reproductive health later in life.The purpose of this presentation is to summarize the effects of phytoestrogens on female reproduction, fertility and behaviour, as presented in the animal, clinical, and epidemiological literature.In the end, participants will gain a deeper understanding of the impact that hormone-mimics such as phytoestrogens have on the reproductive physiology and fertility of developing and adult females.