<p>This research investigates the impact of the integration of Green Supply Chain Management (GSCM) and Environmental Management Practices (EMP) in enhancing Enviropreneurship Performance (EP) in SMEs in the Indonesian tourism sector. This research also explores the role of Firm Size in moderating the relationship between GSCM and EMP. This research aims to examine how these variables influence each other and contribute to implementing sustainable practices. This research used a quantitative approach, with data collection through an online survey conducted on 278 SMEs in Indonesian tourism sector. The data was analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM) to test the research model and the proposed hypothesis. The results showed that implementing GSCM and EMP positively and significantly influenced EP. In addition, EMP was proven to act as a mediator in the relationship between GSCM and EP. Meanwhile, Firm Size was also proven to moderate the relationship between GSCM and EMP, which shows that larger firms have more resources to implement sustainable practices effectively. The scope of this research is limited to SMEs in Indonesian tourism sector. Therefore, the findings may not fully reflect conditions for other sectors or countries. This research provides empirical evidence of the positive effect of implementing sustainable practices on business performance and provides practical insights for SMEs to integrate sustainable practices into their business operations.</p>