Résumé : Infertility affects about 15% of couples seeking to obtain a pregnancy. In 20 to 50% of the cases, a deficiency in sperm quality or a male factor is observed. In more than 15% of cases, the causes of infertility remain unknown. Many factors, related to lifestyle or environment, may influence male fertility by leading to deleterious quantitative or qualitative effects on sperm. Among them, a recent and growing interest is put on weight and nutritional status of male partners of infertile couples. Oxidative stress plays a key-role in the involved mechanisms. An unbalanced pro-oxidants/antioxidants ratio, notably due to inadequate dietary intakes, can have deleterious consequences for male fertility.