Phytoestrogens are nonsteroidal plant-derived compounds found in various forms in humans and animal foods. Phytoestrogens bind with mammalian estrogen receptors (ER) as they are structurally like mammalian estrogen and alter multiple mechanisms and processes, causing several disorders and diseases. Studies in humans and animals have revealed that dietary phytoestrogens play a crucial role in preventing hormone-dependent diseases and disorders such as menopausal symptoms, osteoporosis, cancer, and heart disease. Despite the potential health benefits, phytoestrogens also have several adverse effects on the reproductive health of males and females. Phytoestrogens bind with ER, interfere with the hormonal regulation of the reproductive organs, and increase the propensity of infertility, abnormal estrus cycle, and anestrous. Phytoestrogens also alter prenatal and postnatal fetal development causing various developmental abnormalities. Several studies investigated the effects of phytoestrogen compounds on reproductive health using animals, humans, and in vitro culture models. Therefore, it is important to summarize these findings for future mitigation strategies against phytoestrogens. This review focuses on the impact of specific phytoestrogens on the reproductive health of males and females and the underlying mechanisms involved in the detrimental effects of various phytoestrogen compounds. Based on the evidence obtained from the literature, we also summarized the findings in the tabular form on different reproductive tissues in males and females, including prenatal and postnatal fetal development. Phytoestrogen Phytoestrogens are a diverse class of nonsteroidal, diphenolic, estrogenic plant compounds, including prenylated flavonoids, isoflavones, coumestans, and lignans [1,2]. They are plant-derived nonsteroidal compounds structurally or functionally similar to mammalian estrogen (E 2), especially 17β-estradiol [3,4]. Phytoestrogens have an affinity for estrogen receptor-α (ER α) and-β (ER β) [3,5,6], peroxisome proliferator-activated receptor (PPAR) family [7-9] and the aryl hydrocarbon receptor (AhR) [9-11]. Phytoestrogens or their active metabolites are known to act mainly on male and female central nervous systems and reproductive systems. Phytoestrogens are poly-phenolic compounds that include over 100 molecules . According to their chemical structure, they are divided into iso-flavones, flavones, coumestans, stilbenes, and lignans (Figure 1) . Several plants consumed by humans and animals contain phytoestrogens . Soybean products are rich in higher concentrations of isoflavones, while flaxseed is rich in lignans, clover contains coumestans , olives contain flavones , and stilbenes are found in cocoa and grape containing products, particularly red wine . Mostly isoflavones from legumes, beans, and bean-containing products exhibit estrogenic activity in animals [17-21]. Second-generation soy foods are made by adding soy ingredients to a wide variety of manufactured foods. These second-generation soy foods such as tofu yogurt and soy noodle contain less isoflavone content [22-24]. Cereals, fruit, and vegetables such as flaxseed (known as linseed) contain a high concentration of lignans [19,25,26], while in whole grain cereals, vegetables, fruit, and seeds have a lesser concentration of lig-nans . After consumption, phytoestrogens are metabolized by intestinal microflora, conjugated in the liver, distributed to various tissues through plasma, and excreted through urine .