This study aimed to evaluate the impact of participatory grant-making on the performance of Partner Organization Projects. The research focused on the Hivos Foundation in Tanzania and examined the essence and nature of the participatory grant-making approach, as well as the processes involved and the impact on project sustainability. The study utilized a qualitative case study methodology, collecting data through document review, in-depth interviews, focused group discussions, and observations. Data analysis methods included content analysis and narrative analysis. The findings of the study revealed several key insights. Firstly, the participatory approach fostered shared responsibility and community engagement, leadership development, innovation, and trust. These factors contributed to effective project implementation, ultimately improving project performance and sustainability. Additionally, the study highlighted the importance of involving non-grantmakers in the grant-making process. The inclusion of external stakeholders at any stage of the process was found to be a crucial component of participatory grant-making, enhancing project performance. The study concludes that the participatory approach can lead to the sustainability of certain project elements, but only when it is used as both a means and an end. It emphasizes that Grantmakers should view recipients of grants not just as beneficiaries, but as agents of change in their communities. The participation of local people in the grant-making process at any stage is essential for fostering