Blockchain technology is increasingly recognized as a transformative tool for improving agri-food supply chain (ASC) performance, particularly in enhancing transparency and traceability. Nonetheless, it has still not been widely adopted in developing nations like Pakistan. This study investigates the impact of blockchain adoption on ASC performance, incorporating transparency as a mediating variable and the Internet of Things (IoT) as a moderating factor within the Unified Theory of Acceptance and Use of Technology (UTAUT) framework. Data were collected from 333 professionals in Pakistan's agri-food sector and analyzed using smart PLS, with mediation and moderation effects. The findings reveal that blockchain adoption significantly improves supply chain performance. Transparency partially mediates this relationship, while IoT strengthens the effect by enabling real-time data sharing and monitoring. The study offers new insights into literature by extending UTAUT through the integration of blockchain and IoT, and by empirically validating their combined impact in a developing economy context. In practice, the results provide practical information to policy makers and industry players with a view to improving efficiency, accountability, and sustainability in the agri-food supply chains.