Ample experimental evidence shows that negative gossip fosters cooperation in groups by increasing individuals’ reputational concerns. However, recent field studies showed that negative gossip decreases organizational citizenship behavior (OCB) among its targets (i.e., people whom gossip is about). Bridging these findings, we study the role of social inclusion in explaining how negative gossip affects targets’ engagement in OCB. Based on social exchange theory, we predict that targets of negative gossip experience low social inclusion. In turn, we propose that low social inclusion leads to low OCB of gossip targets. Results of three studies, a correlational study (N = 563), a laboratory experiment (N = 85), and an online scenario experiment (N = 597), showed that being the target of negative gossip reduced social inclusion and indirectly decreased OCBs. Our multi-method approach bridges findings from research conducted in organizations and in laboratory experiments and offers a more nuanced understanding of the effects of negative gossip on targets’ behavior. We show that due to its detrimental effect on targets’ social inclusion, negative gossip may not be as effective for enabling sustainable cooperation as experimental studies claim it to be.