Fringe stakeholders with limited resources, such as grassroots organizations (GROs), are often ignored in business and society literature. We develop a conceptual framework and a set of propositions detailing how GROs strategically gain legitimacy and influence over time. We argue that GROs encounter specific paradoxes over the emergence, development, and resolution of an issue, and they address these paradoxes using cognitive, moral, and pragmatic legitimacy strategies. While cognitive and moral strategies tend to be used consistently, the flexible and paradoxical use (...) of pragmatic strategies has important consequences, both for GROs’ legitimacy and for their potential influence over powerful organizations associated with them. We enrich our framework with the help of two illustrative cases and discuss the implications of the framework for GROs’ legitimacy strategies in business and society literature. (shrink)