The present study evaluated oxidative stress and apoptosis in Sertoli cells that had been exposed to sodium fluoride (NaF). After TM4 Sertoli cells were exposed to two doses of sodium fluoride (4 ppm and 20 ppm, equivalent to 1.81 mg F/L and 9.05 mg F/L, respectively) in the presence and absence of 50 mu M vitamin C for two different exposure periods (24 hr and 48 hr), cell viability, cell proliferation, cytotoxicity, lipid peroxidation, and reactive oxygen species were measured and the apoptosis/necrosis rate was calculated. A significant decrease in the Sertoli cell viability was found with the high dose of NaF (20 ppm). The fluoride ion also caused oxidative damage by increasing cytotoxicity, reactive oxygen species, and lipid peroxidation in a dose-and time-dependent manner. The apoptosis/necrosis rate was significantly increased in both NaF groups. Vitamin C, a strong antioxidant, had a protective effect against the fluoride-induced damage in the Sertoli cells including the increased apoptosis/necrosis rate. In conclusion, the present study showed that oxidative stress plays a possible role in the apoptosis of Sertoli cells induced by NaF, and that these effects can be suppressed with vitamin C.