Preeclampsia (PE) is a multisystem disorder that remains a major cause of maternal and foetal morbidity and death. To date, no treatment has been found that prevents the development of the disease. Endothelial dysfunction is considered to underlie its clinical manifestations, such as maternal hypertension, proteinuria and edema; and oxidative stress has been increasingly postulated as a major contributor to endothelial dysfunction in PE. A large body of research has investigated the potential role of antioxidant nutrients in the prevention of PE in women at high increased risk of the disease. Therefore, the present study was primarly designed to assess the potential benefit of antioxidant supplementation on markers of placental oxidative stress in an in vitro model of PE, since we previously found that endothelin-1 (ET-1) is able to trigger the placental secretion of stress molecules. In this regard, we evaluated the effects of vitamin C, vitamin E and N-acetylcysteine (NAC), alone or in combination, in placental villi culture after exposure to ET-1. The effect of antioxidant nutrients on trophoblast cells proliferation and vitality was also evaluated. The results obtained suggest that in a pathophysiological condition, such as PE, the deleterious effect of reactive oxygen species may be counteract by an antioxidant therapy, and there is the need to investigate the optimum dosing and timing of antioxidants administration, since an inappropriate antioxidant treatment in pregnant women may have deleterious consequences, reducing placental cells proliferation until to cell death.