One of the important issues facing the Islamic world today which is essential to be discussed and critiqued is how to communicate and coexist with non- Muslims, concerning various aspects: political, cultural, economic, legal and so on. For example, from among the four countries which are Islamic republics (Iran, Pakistan, Afghanistan and Mauritania), it seems that the investigation of the attitude of the constitutions of the two countries of Iran and Pakistan-whose laws are in accordance and in coordination with Islam more than others- towards this issue is necessary. The constitutions of these two countries have pointed out to the rights of non-Muslims living in those societies in several articles, and have determined the Muslims' manners and duties towards the non-Muslims, while giving them some rights in general, as they are the citizens of the Islamic community, these articles suggest the Muslims' attitudes towards non-Muslims regarding their behavior and interaction with them. Now, the fundamental question of this research is: Have the constitutions of Iran and Pakistan, as two Islamic republics, and as required by the Communications Age, endeavored to provide the rights of non- Muslims adequately? And the hypothesis of this article is: the constitutions of Iran and Pakistan, as required by the I.C.T. Age, need to be reviewed and revised for the completion of the fundamental rights of non-Muslim citizens.In the present paper, by investigating the constitutions of Iran and Pakistan as two Muslim countries whose official religion is Islam and all of their laws and regulations must be based on the Islamic principles (according to Article 4 of the constitution of Iran and Article 227 of Pakistan's constitution) we cover the points of similarity and distinction between them as well as their strengths and weaknesses on the field of non- Muslims' rights.This research has been carried out by employing the descriptive- comparative method and by using library sources.