The concept of an Islamic republic is a very popular concept in the Middle East and in regard of the immense legitimising effect Islam can muster in conservative Islamic societies, it is possible that we will have to face more Islamic republics in the future. Although there is great concern regarding the spread of the concept in the West, literature is scarce on the question which specific aspects render a republic an Islamic republic. In this essay this question is examined by a comparative analysis of the Iranian and the Afghan Constitution. In order to examine the consequences of the establishment of an Islamic republic for universal human rights as they are established in the Universal Declaration of Human Rights and both UN Human Rights Covenants, these consequences are classified into three categories. First there are consequences which are positive in regard to human rights. These are mainly social rights and the respective state obligations, for instance the obligation to create social justice, which is a prominent feature of Islam. These aspects seem to contribute most to the popularity of the concept in the Middle East. The second category of consequences is formed by regulations which are in a clear breach of international human rights, such as discriminations against followers of non-Islamic beliefs. The third category of regulations is composed of such provisions which potentially may infringe international human rights depending on the interpretation of Islamic law. The establishment of Islam as the state religion and the guarantee of the conformity of legislation with Islamic criteria can be classified into this category of regulations. A comparison of the two constitutions under these categories demonstrates that social rights are featured very prominently in the Iranian Constitution. However, the two Constitutions most decisively differ in regard to the third category of consequences since the Afghan Constitution gives the protection of human rights a high priority which is virtually unknown in other constitutions of the regions. This might facilitate the protection of human rights in cases in which there is conflict between the Islamic law and human rights. The Iranian Constitution on the other hand unconditionally clarifies that in cases of conflict Islamic law prevails. Additionally, the Afghan Constitution gives the directly elected representatives of the Afghan people the power to influence the interpretation of Islam decisively, since the judges of the Supreme Court who are competent to review the compatibility of the legislation with Islamic criteria are appointed by the elected President of the Republic with the consent of the Lower House of Parliament. In contrast, in Iran this competence rests with the religious scholars of the Guardian Council, who are appointed by the Religious Leader whose term of office is neither restricted nor is he elected directly by the people. The outcome of the analysis is that although the concept of an Islamic Republic is problematic in regard to international human rights, there are rights which are supported by the principle, namely social and educational rights. Moreover, as the analysis of the two constitutions reveals, there are decisive differences in regard to the protection of human rights. While the Afghan Constitution which gives a prominent role to human rights is very positive and should be regarded as a model for the region, the Iranian Constitution is much more problematic. Hence, what is decisive are the concrete constitutional regulations and guarantees of human rights in particular in case of conflict with Islamic law and only to a much lesser extent the decision whether a republic is referred to as an Islamic republic. [ABSTRACT FROM AUTHOR]