In order to explore the effect of neonatal androgen administration on oocyte quality, ovulation induction and in vitro fertilization (IVF) were performed in androgen-sterilized mice. Androgen sterilized mice were produced by the subcutaneous injection of testosterone propionate (TP) at 5 days of age and ovulation induction was performed by pregnant mare's serum gonadotropin (PMSG)-human chorionic gonadotropin (hCG) treatment at 9 to 13 weeks old. The number of oocytes ovulated in TP-injected mice was 19.9 +/- 2.0 (Mean +/- SE) and was significantly less than that in normal mice (37.8 +/- 1.9; P < 0.01). The fertilization rate of oocytes retrieved from TP-treated mice (38.8%) was significantly lower than that from normal mice (60.3%; P < 0.01). These results indicate that neonatal androgen treatment has a detrimental effect on oocyte maturity.