Research SummaryDrawing on social cognitive theory, this study develops and tests a model to clarify the boundary conditions and mechanisms through which coworker entrepreneurship influences employee entrepreneurship. Two time‐lagged field studies support our predictions: employee moral attentiveness moderates the effect of coworker entrepreneurship on employee entrepreneurship, with coworker entrepreneurship reducing employee entrepreneurship among those with high moral attentiveness and increasing it among those with low attentiveness. Additionally, deontic injustice mediates the negative relationship when moral attentiveness is high, while vicarious learning mediates the positive relationship when attentiveness is low. These findings indicate that interpersonal influence in organizations is much more complex than the simple “Monkey see, Monkey do” explanation of social learning and emphasize the need to integrate moral and justice considerations into entrepreneurship research.Managerial SummaryThis study provides a comprehensive understanding of the dual impact of coworker entrepreneurship on employee entrepreneurship. It suggests that employees characterized by high moral attentiveness are more likely to perceive deontic injustice when witnessing coworker entrepreneurship, thus prompting resistance to imitating such behavior. Conversely, employees with low moral attentiveness are prone to engage in vicarious learning, potentially leading them to mimic their coworkers' entrepreneurial actions. These findings highlight crucial factors that may deter employees from replicating their coworkers' entrepreneurial endeavors and offer valuable insights for managers seeking to mitigate the negative influence of coworker entrepreneurship and its spread within organizational contexts.