Issue sellers employ a variety of tactics to create internal support for issues they seek to advance within an organization. While the relationship between internal issue “sellers” and “buyers” has been examined in prior work, we address a crucial omission in this body of literature, namely how issue sellers engage with external stakeholders to influence internal issue selling. We study corporate social responsibility (CSR) managers, their organizational counterparts who are expected to implement CSR, and external stakeholders (in our study non-governmental organizations). We find that issue sellers have three issue-selling tactics at their disposal that they employ dynamically and depending on internal buyers’ perception of the issue: First, mobilizing external stakeholders when internal support for the issue is low; second, buffering external expectations when they are incongruent with internal requirements; and third, moderating between external stakeholders and internal buyers when issues are difficult to implement. Our contribution is to explain why issue sellers’ role vis-à-vis internal buyers and external stakeholders can be better understood as that of “issue brokers” when they navigate strategically between external stakeholder expectations and organizational goals. This advances the issue-selling literature and research on brokerage roles and contributes to individual-level research on CSR.