Overpopulation is one of the most serious issues impacting both the present day and the future. It is closely connected to ecological perspectives on human life on Earth. However, the “reproductive mission” of humankind has constituted a biological and moral imperative in all cultures and especially in the Abrahamic monotheisms and their laws. Combining these two divergent ‘lines of force’ inevitably also produces different ways of interpreting and living human rights. This paper outlines the interplay among Islamic law, human rights, social and religious habits and the challenges of overpopulation, considering the population transition laws in Iran, from 1967 up to today.