Iran famines are as old as the history of the country. A great deal has been said about the causes of the famines. Most are concerned with the most superficial explanation of the famines, namely the wrath of the nature; and all that has gone to the Iranian people turned out to be the outcome of the unkindness of the Mother Nature. Such explanations are somewhat far from the reality. It is true that Iranian plateau, compared with parts of the world: namely Northern and Western Europe and also the world average, has less rainfall. Therefore, some of the periodical famines have occurred because of that. Still it is far from reality if we ignore the role of the various social factors in the creation of Iranian famines. The social factors sometimes have been the cause and trigger of the famines (primary or external factors) and sometimes have acted as intensifiers (secondary or side factors). In this article we have explained the significant role of the social factors in originating and continuing the greatest and most dreadful famine of 1871.