Iran is one of the top refugee-hosting countries in the world. After the beginning of war in Afghanistan in the late 1970s and 1980s, Iran opened its borders to Afghan refugees. Unlike Pakistan, Iran allowed Afghans to enter the country and reside in the mainland, in cities, and villages, instead of accommodating them in border camps. That was an unusual decision that was not effectuated by Iran's government during the 1990s ongoing wave of immigrations. This paper explores the main causes for the open door policy adopted by Iran in the mentioned period and investigates the consequences that resulted from this policy. Unlike many scholars who claim the immigration policy of the time to be the result of either ideological or calculated decisions, this paper argues that there was no other alternative for the new government in the peculiar circumstances of a post-revolutionary country.