This chapter investigates the impact of FinTech integration on the accessibility and sustainability of microfinance institutions (MFIs) using a case study approach and secondary data. The chapter examines how the use of FinTech solutions by MFIs have enhanced the accessibility of microfinance services by the poor and financially excluded individuals and groups. The chapter also evaluates the potential impact of FinTech integration on the financial sustainability and operational efficiency of MFIs. The chapter identifies key challenges of microfinance-FinTech integration such as high initial investment costs, cybersecurity risks, regulatory complexities, and the potential for over- indebtedness. This investigation provides insights into the opportunities and challenges that MFIs face in adopting FinTech solutions to achieve their aim of enhancing financial inclusion and long- term sustainability in the evolving digital landscape.