Environmental corporate social responsibility (ECSR) has recently gained traction among academics, practitioners, and policymakers as a critical driver of sustainable development. However, the impact of ECSR on actual pro-environmental behavior remains unclear in the literature, particularly in the context of developing countries. Grounded in the social exchange and social network theories, this study examines the effect of ECSR on pro-environmental behavior via the mediation of a green shared vision and the moderation of two types of personal ties (business ties and political ties). Data was collected and analyzed from 375 manufacturing sector employees in Pakistan at two time periods. The results show that ECSR (at time 1) drives actual pro-environmental behavior (at time 2). Specifically, implementing ECSR can significantly enhance an employee's pro-environmental behavior via its green shared vision. In addition, business ties were found to strengthen the relationship between ECSR and green shared vision. In contrast, political ties were revealed to weaken the connection between ECSR and green shared vision, thus affecting sustainable development objectives. Our findings provide implications for policymakers and practitioners to promote ECSR in developing countries.