Abstract: Can religion generate social capital and promote the development of civil society? Beyond acknowledging the global prevalence of religious civil society organizations (CSOs) in service provision, the vast literature on civil society has not engaged with the role of religion in fostering social capital. Rather, political scientists have focused on debating the outputs of civil society, especially with regards to democratization. In this paper, we examine the impact of religious practice – specifically religious pilgrimages – on the cultivation of associational life and voluntarism in host cities. We argue that religious pilgrimages can promote civil society development through two mechanisms: first, the “localized pilgrimage” mechanism explains how pro-social values associated with the pilgrimage are continuously reinforced in the local population, resulting in the establishment and promotion of CSOs that promote those values. Second, the “organizational capacity” mechanism explains how locals acquire skills from organizing pilgrimage activities that they later utilize in the off-season. We apply this theory to two cases: the Arba’een pilgrimage in Karbala, Iraq and the Kanwar Yatra pilgrimage in Haridwar, India. We draw on various sources of data – including public opinion polling, NGO data, and interviews – to paint a picture of associational life in each of these cities. In order to isolate the impact of the pilgrimage, we then employ a “most similar” case study design to compare each of Karbala and Haridwar to a city that is similar along most measures, but that does not experience pilgrimage activity, Al-Hillah in Iraq and Kanpur in India.