Nitrates and nitrites occur naturally in the environment. They are important plant nutrients and vegetables account for about 70-90% of the total estimated dietary nitrate intake. Nitrate plays an important role in the nutrition and function of plants. Vegetables rich diet has been described beneficial for longevity and overall health of humans. The positive effects of vegetables may be attributed, in part, to inorganic nitrate present in green leafy vegetables. The nitrate and nitrite level in vegetables varies significantly from type of vegetables, demographic area and season. Nitrate and nitrite content of vegetables has been reviewed and an attempt was made to establish nitrate to nitrite ratio present in vegetables.