This thesis aims to explore the role and performance of the International Islamic Relief Organisation of Saudi Arabia (IIROSA) in Pakistan regarding its social development and humanitarian assistance policy in the 9/11 era. Furthermore, it explains the opinion and stand of IIROSA regarding religious radicalization and the strategies taken to invalidate the allegations of being a radical organisation. In this context, this research elaborates the measures IIROSA has taken to control their financial management system and the steps it is taking to avoid radical and extremist trends in religious activities. The major contribution of the study is that it addresses the lack of research on Transnational Islamic Charities in the context of development initiatives. This research deals with the qualitative approach to empirical study. Data collection followed four techniques: document analysis, observation, in-depth interviews and focus group discussions. The main participants of the empirical study were stakeholders of IIROSA in Pakistan including administration, workers and beneficiaries of projects. Employing Social Movement Theory, this thesis, emphasises the identity of Transnational Islamic Charities as social actors/Islamic social institutes. It argues that as social actors, Islamic charities are focused on social and humanitarian programmes with regard to the Islamic interpretations of human welfare quoting the Quran and Hadith. Additionally, this study, by elaborating the religion and development of a nexus framework, explores and examines the role of religion in development in relation to the particular social setup of Islam for socio-economic benefits and welfare of human beings. It proposes that religion still has an importance in the development sector as demonstrated by the existence of faith-based aid organisations and how they are attempting to design their activities in the pattern of mainstream development organisations. This thesis explores activities of IIROSA in Pakistan regarding the orphans’ programme, educational activities, health care initiatives and disaster relief projects. All these effective programmes closely mirror the pattern and principles of mainstream development organisations throughout the world. However, with regard to girls’ education and women’s empowerment, IIROSA needs to take more assertive measures to strengthen its social development programme. IIROSA is determined to maintain its position and membership in the United Nations and other international organisations. In the aftermath of the 9/11 events, it had to face allegations and consequences when accused of being a radical organisation. The outcome was that IIROSA had to be more sensitive regarding matters of religious radicalization. In order to remove the stigma associated with religious radicalization; this organisation is attempting to improve its work and standing in the hope that it will be recognised world-wide as a humanitarian, impartial and neutral relief organisation.