The decline of Islamic-Iranian civilization has long been considered by the thinkers. The present study, based on the published works of these two thinkers with the method of comparative study, seeks to compare their views on the causes of the decline of Islamic-Iranian civilization and ways out of it. The findings show that they have divided the degenerative factors into two categories: internal and external. They share in introducing elements such as authoritarian rule and colonialism as factors of degeneration, but in some cases they also have differences. In the section on internal factors, Shahid Motahari emphasizes on factors such as distorting the teachings of Islam, harmful support of religion, etc., and Nasr emphasizes on issues such as the decline of the institution of religion, the decline of institutions, and so on. In the section on external factors, Shahid Motahari mentions the role of non-Muslims, domination and political colonization, but Nasr mentions the influence of Western science and technology and cultural damage in the light of globalization. In the solutions section, each of them has their own opinions.