Although Islamism could be traced back to the seventh century when prophet Mohamad died and conflict between Shia and Sunni started, the recent growth of Islamism and emerging of new phenomena such as establishing Muslim Brotherhood in Egypt in 1920s, Iranian Islamic revolution in 1979, and some other Islamists groups like Hezbollah, and Al-Qaida highlighted the importance of Islamism. Moreover, forming the new Islamists in Syria, Iraq, and Yemen after the Arab uprising in 2010 which intensified the conflict between Shia and Sunni increased the concerns over increase in sectarianism in the Middle East. Considering the significance of Shia groups in recent movements, it is important to have a deep and comprehensive understanding of the nature and function of Shia Political Islam. Despite internal and external concerns, Shia Political Islam has emerged and continued to have control over power in Iran for more than four decades. The post-revolutionary Islamic government has been able to keep its power through reviving the Shia Movement since the 1979 Islamic revolution. Therefore, this thesis asks ‘how has Shia political Islam managed to survive in Iran over the past four decades? The answer to this question relies specifically on understanding the nature of Shia ideology and how the Shia control entities’ access to petrodollars. The study aims to clarify the concept of Shiism and explain the mechanism of the survival and continuation of the Shia movement in Iran through the lens of Social Movement Theory. This thesis argues that the essential mobilisers of the Shia Movement like the IRGC, the Basij and mosques have succeeded in sustaining the survival of the Shia Political Islam. The durability of this political approach lies in actively reviving the origins of the Shia movement, utilising Shia values, religious symbols and holy events such as Ashura, and financially rewarding the Movement with petrodollars. The mobilisers, especially the IRGC, use these values as a steering fuel to run the Shia Movement and suppress any security threat to its survival. For instance, after the 2009 presidential elections, the Green Movement was a serious security threat to the Islamic Republic and the political approach Shia political Islam. However, the IRGC and the Basij employed Shia symbols to mobilise their social base in a counter-movement in 2019 to overcome the threat of the Green Movement. The thesis concludes that if the Shia mobiliser organisations keep supporting the Shia Movement by utilising Shia values, religious symbols, and available economic resources such as petrodollars, Shia political Islam will stay resilient and survive.