1. Nitrate and nitrite may contribute via nitrosation to the human exposure to N-nitroso compounds, especially nitrosamines, which are suspectd to be human carcinogens. 2. Since certain foods contain traces of nitrosamines, one should take the several points into consideration in evaluating the risk. 3. Nitrites, which can appear in the because of natural occurrence or deliberate addition, can react under the acidic conditions of the normal stomach with secondary amines to form nitrosamine. 4. Among the foods esamined, nitrate-nitrite treated meat products cooked bacon, and salted and dried fish are the main contributors of nitrosamines in our diet. 5. Consequently, in order to minimize human exposure to these chemicals, it is obviously essential to develop the alternative sources of nitrite in cured meat products. Thus the emphasis should be placed upon the most effective use of nitrite in curing with the use of acceptable inhibitors of nitrosation such as ascorbc acid or $alpha$-tocopherol.