Timed pregnant Balb-C mice were treated from day 1 of gestation to 7 days after delivery with the endocrine disruptor bisphenol a (BPA) (100, or 1,000 microg/kg/day). After delivery, pups were hold for three months; then, ovaries were analyzed in their entirety. We found that in the ovaries of BPA-treated animals the number of primordial follicles and of developing follicles was significantly lower than in the untreated animals. Moreover, the number of atretic follicles was significantly higher in the treated animals. Finally, we found that the animals displaying endometriosis-like phenotype had a more severe impairment of the ovaries in term of number of primordial and developing follicles in comparison with the other mice exposed to BPA. In conclusion, we describe for the first time a complex phenotype in mice, elicited by pre-natal exposition to BPA, that includes ovarian lesions and endometriosis. Considering the high incidence of endometriosis and of the premature ovarian failure associated to infertility in these patients, the data showed prompt a thoroughly reconsideration of the pathological framing of these lesions.