Over recent years increasing evidence suggests that xeno-oestrogens including alkylphenols, such as nonylphenol and octlyphenol (OP), may represent a threat to the health and reproductive function of humans, domestic animals and wildlife populations. To date most attention has focused on the effect of these endocrine disrupting compounds (EDCs) on male reproductive health. In contrast, hardly any attention has been paid to the potential adverse effects that these compounds may exert in females, where the end points are easier to measure than in males, and where oestrogen modulated diseases such as breast cancer, are of such importance to humans. This is also despite evidence from a number of species, including humans, that exposure in utero to the potent synthetic oestrogen diethylstilbestrol (DES) has profound and long-term effects on ovarian morphology, folliculogenesis, fertility, and pregnancy outcome of female offspring.