The paper aims to investigate the integration of sustainability management and lean practices in small and medium enterprises (SMEs) and its impact on supply chain performance. The study also explores the mediating role of process innovation in this relationship. Sustainability has gained significant attention in recent years as organizations strive to align their operations with environmental and social responsibility goals. Similarly, lean practices have been widely adopted to streamline processes and eliminate waste in supply chains. However, limited research has focused on the simultaneous integration of sustainability management and lean practices in SMEs and their combined effect on supply chain performance. The research adopts a quantitative approach, which involves collecting survey data from a sample of SMEs operating in diverse industries. Statistical analyses, including structural equation modeling, are conducted to examine the direct and indirect relationships among sustainability management, lean practices, process innovation, and supply chain performance. Through the lens of SMEs, the research examines how the integration of sustainability and lean practices fosters competitive advantages and sustainable performance outcomes in the supply chain context. The findings contribute to both theoretical and practical domains by shedding light on the mechanisms through which sustainability and lean practices synergistically influence supply chain performance. For SMEs, the research offers valuable insights into harnessing sustainable and lean principles to achieve operational excellence and long-term success. Ultimately, this study advocates for a holistic approach to supply chain management that embraces sustainability, lean thinking, and process optimization to promote enhanced performance and a more sustainable future for enterprises of all scales.