The need for creating an environment for sustainable growth of startups for the well-being of an economy cannot be overemphasized. Many experts have proposed that corporate social responsibility (CSR) practices are integral to the long-term survival and success of startups (Jenkins, Confronting the challenges of participatory culture: Media education for the 21st century, 2009). At the same time, they also argue that it is very challenging for startups to adopt these practices effectively (Salamzadeh, 2015). In this background, this is an empirical study of promoters of startups in a developing economy, India, to test the linkages between CSR practices and startup success. The study empirically examines the perception of the promoters regarding these linkages, studies the CSR practices adopted by them, and identifies the challenges faced by them in using CSR for sustainable growth. The findings of the study reveal that there is a distinct relationship between startup success (sustainability) and CSR activities. The article empirically proves that the sustainability of a startup is positively dependent upon internal, external, and environmental CSR initiatives. It also concludes that definite structural interventions are required by policymakers to achieve the twin objectives of startup success and societal well-being.