The purpose of this study is to analyze the relationship between eco-efficiency and sustainability performance, the relationship between eco-supply chain management and sustainability performance and analyze the mediating role of Eco-Supply Chain Management on the relationship between eco-efficiency and sustainability performance. The study method is a quantitative survey which is executed through the partial least square structural equation model (SEM-PLS) with a statistical data processing tool, namely SmartPLS 4.0 software. Research data was obtained by distributing online questionnaires through social media designed using a Likert scale of 7. Respondents in this study were 590 SMEs owners in Java Island, Indonesia. The results of the study indicate that eco-efficiency had a positive and significant effect on sustainability performance, green supply chain management (GSCM) had a positive and significant effect on sustainability performance. GSCM also plays a full mediating role in the relationship between eco-efficiency and sustainability performance. This research is expected to be a source of reference for further research in discussing issues related to the implementation of eco-efficiency and GSCM.