Drawing from social exchange theory, this paper proposes and empirically examines organizational citizenship behavior as a possible mechanism to explain the association between suppliers’ socially responsible behavior and organizational performance. Data were collected from companies in the apparel supply chain in Pakistan, a developing country. Findings show that social responsibility standards have a positive impact on organizational citizenship behavior which in turn positively impacts operational and quality performance. Further, a mediation relationship is shown. This research informs practitioners that social responsibility initiatives instigate deep-rooted changes promoting social-friendly behaviors impacting firm performance. Suggestions for future research are discussed.