Choline and methionine are essential nutrients for many mammals. In this work we aimed to evaluate 1^ role of choline and methionine in counteracting the oxidative stress induced by hydrogen perowein bovine mammary epithelial cells. BME-UV1 cell line has been previously used as in vitro model for mammary epithelium. First of all, BME-UV1 were exposed to increasing concentrations of hydrogen peroxide to establish half lethal concentrations at 24, 48 and 72 hours. Furthermore, BME-UV1 cells were incubated with increasing amounts of choline and methionine in order to identify the most effective concentrations in term of cell viability. In this respect, two combinations of choline and methionine have been selected: a Low Choline/Methionine dosage and a High Choline/Methionine dosage, providing respectively to 500 yu.M/715 ytiM and 1000 ytiM/1430 ytiM of choline and methion­ine. After that, BME-UV1 treated with Low Choline/Methionine dosage and High Choline/Methionine dosage were exposed to selected concentrations of hydrogen peroxide for the following 24, 48 and 72 hours. After 48 h and 72 h of treatments BME-UV1 viability was significantly (P< 0.05) enhanced on average by 21% and 25.8% at the lowest range of hydrogen peroxide concentrations tested. At the highest concentrations of hydrogen peroxide used only a slightly increasing of BME-UV1 viability has been observed. After 24 h of incubation, choline and methionine treatments did not significantly influenced cell viability. Our results indicate that choline and methionine could play a role in counteracting oxidative damage induced by hydrogen peroxide in bovine mammary epithelial cells, even though the correct mechanism needs further investigations.