In each country entry, residence and transit of foreign nationals are a question that has a direct relation with security and political system of the country.  In this respect, each country regulates its laws relating to the entry of foreign nationals according to its necessities.  The Islamic Republic of Iran, according to the Law of 1310 Concerning the Entry and Residence of Foreign Nationals, requires procedures such as visa which allow the State the possibilities of controlling the entry and the authorised residence of foreign nationals in the country.  However, in recent years, because of the regional changes and the gap of a rigid control of the State in its long borders, many citizens of the neighbour countries without respecting the above-mentioned law entered  Iran.  Obviously, many of these people find the title of displaced or refugee people falling within the framework of United Nations high commissioners for refugees (UNCHR) and accordingly they find a legal status in Iran. On the contrary, the unauthorised entry and residence of foreign nationals are subjects which confront our State with many challenges especially legal challenges. In line with the duty of the State to preserve and defend the borders and the territorial integrity of the country, the best solution to reduce the negative effects of the presence of these foreign citizens is the reinforcement of the borders control system. Moreover, certain changes of the laws seem necessary especially with regard to the laws of nationality.