Stomach cancer remains a common type of cancer, though its incidence has been halved in the last forty years. It is unevenly distributed throughout the world. In France, it holds fifth place among cancers and there are 8700 new cases each year. Helicobacter pylori infection, a high salt intake as well as an inadequate diet take part in the first stages of carcinogenesis. Later on, nitrates and nitrites, polycyclic hydrocarbons, alcohol, tobacco and bilc acids are incriminated. The protective role of vegetables and fruit has been well established. The protective role of vitamin C and beta-carotene is currently undergoing evaluation in subjects suffering from precancerous conditions such as dysplasia and incomplete intestinal metaplasia. The development of a vaccine against Helicobacter pylori induced infection also represents an important goal.