Microfinance institutions (MFIs) are critical in promoting financial inclusion and socio-economic development, particularly in marginalized regions. The success and effectiveness of these institutions heavily rely on leadership and group management. This study examines the relationship between leadership, participation, group management, morals, and key success factors for MFIs in Chaiyaphum, Thailand. A quantitative study used a questionnaire to collect data from 396 MFIs. The study revealed a substantial positive correlation between leadership and group management and key success factors. Notably, leadership exhibited the strongest correlation among the variables analyzed. This implies that effective leadership practices and efficient group management significantly contribute to achieving key success factors in microfinance institutions. This study also developed a predictive equation that demonstrated a remarkable level of accuracy in predicting key success factors for MFIs. The equation accurately captured and predicted the interplay between the identified factors and the key success factors for microfinance institutions. The findings highlight the critical importance of leadership and group management in driving the key success factors for MFIs in Chaiyaphum. It underscores the significance of strong leadership capabilities and the implementation of effective group management strategies to enhance the overall performance and sustainability of MFIs. This study also has practical implications for developing and managing MFIs in Chaiyaphum and beyond. By leveraging the findings of this study, policymakers, practitioners, and stakeholders can gain valuable insights into the factors that contribute to the success of microfinance institutions and make informed decisions to support their growth and impact.