The main purpose of the chapter is to investigate whether business model innovation has any effect on the sustainable performance of small and medium enterprises (SMEs) in developing countries. The chapter also explores the mediating role of green finance on the relationship between business model innovation and sustainable performance of SMEs. The research was guided by the positivist philosophy. Structured questionnaires were used to gather data from 319 SME owner/managers operating in Harare, Zimbabwe. After completing data collection, SmartPLS4 was used for confirming the study hypotheses. Based on the analysis, the results exhibited that business model innovation positively impact sustainable performance. The analysis also supported that green finance mediates the business model innovation and sustainable performance relationship. By providing insights into SMEs in the Zimbabwean context, this chapter enhances the prevailing knowledge on the connection among the study’s three variables; business model innovation, green finance and sustainable performance. This analysis contributes to addressing SDG13 (Climate Action) by integrating green finance into the framework of business model innovation, thereby supporting efforts to combat climate change and mitigate its impacts. Additionally, the study also aligns with SDG9 (Industry, Innovation, and Infrastructure). The study underscores the importance of developing robust and resilient infrastructure, which is integral to advancing sustainable economic growth and fostering innovation in developing countries. Through these contributions, the study enriches the discourse on sustainability and management within the context of SMEs. Policy interventions and stakeholder engagement are essential to fully realize the potential of BMI in contributing to a sustainable future for SMEs in developing countries.