The idea of food security has been circulating for a long time and the right to adequate food and to be free from hunger has been repeatedly affirmed and reaffirmed in a number of documents adopted by the United Nations. Despite the enormous efforts in the past decades by various international organisations, government and non-government organisations, unfortunately, today there are still more than 800 million people throughout the world, most of them in developing countries, who do not have enough food to meet their basic nutritional needs. Among the 800 million, more than 30 percent are from India and China. It is these poor people who have great difficulty in obtaining an adequate food for basic human requirements and who need to be helped by the public grain distribution systems administered by the governments. However, various recent reports demonstrate that the public distribution systems in India and China do not seem to have properly ensured the food security of the poor. In this paper, we highlight and compare major features of the public grain distribution systems in these two most populous countries and investigate how the public grain distribution systems can be most effectively used to ensure the food security of the poor.