Aligning with Sustainable Development Goal 5, which aims to 'achieve gender equality and empower all women and girls', this study examines the impact of board heterogeneity on the sustainability of 794 microfinance institutions in 22 Sub-Saharan African countries from 2010 to 2018. Using the panel-spatial correlation consistent estimation technique to correct for incidences of crosssectional dependence, heteroscedasticity and serial correlation, the findings reveal that gender heterogeneity in the boardroom exerts a positive and significant influence on the sustainability of microfinance institutions in Sub-Saharan Africa. In addition, factors such as the portfolio quality and the level of corruption in the domiciled countries threaten microfinance sustainability while its total asset base and leverage enhance it. In part, the study suggests that policy discussions on microfinance sustainability should emphasise ensuring increasing participation of women in the boardroom.