The main objective of this paper is to study demographic transition and its policy implications
in Iran. Data are mostly taken from the United Nations population projection: the 2010
revision, results of Iran’s population Census, and demographic estimates by the scholars for
the country as a whole. Findings show that Iran is on the eve of the third stage of demographic
transition. Window of opportunity opened to the population in 2005, will remain open for
almost four decades, and will close at the mid 21st century. According to the findings of this
study, the management of window of opportunity should be the first priority of the government’s
population policy. Considering the positive momentum of population growth in Iran, although
experiencing below replacement level fertility will have consequences in the long term in many
areas such as populations aging, but the fear of zero or negative population growth at least
until a few decades would be anachronistic.