In a previous study, we found that early life exposure to low-dose diethylstilbestrol accelerated onset of abnormal estrous cycles in female C57BL/6J mice. In order to observe the ovarian aging of mice exposed to substances on the candidate list for endocrine-disrupting properties, neonates of C57BL/6J mice were orally administered bisphenol A (BPA) at doses of 5 and 50 μg/kg/day. As a result, normal ovarian aging was observed in females treated with BPA. However, females treated with 5 and 50 μg/kg/day of BPA showed modified T-cell differentiation in the thymus. These results suggested that early life exposure to low-dose BPA did not induce premature ovarian failure but modified T-cell differentiation in female mice.