This study examined the effect of stakeholder management on the performance of Non-Governmental Organizations' health care projects in Nairobi City County, Kenya. Specifically, the study aimed to research how stakeholder identification, participation, communication, and stakeholder monitoring impacted the performance of Non-Governmental Organizations' health care projects in Nairobi City County, Kenya. The research utilized a descriptive research design. The target population for the study was 47 projects. The respondents consisted of 47 project managers and 47 program officers. Data were obtained through a descriptive research design. Questionnaires were administered to respondents. The data obtained were cleaned and analyzed using descriptive statistics and inferential statistics. Conclusions and recommendations were drawn from the results of the analysis. All ethical standards were maintained to ensure the reliability of findings. Generally, there was a positive perception, with stakeholders expressing confidence, enthusiasm, and optimism. High levels of stakeholder involvement in project planning, common understanding, contribution, training, and positive outcomes. High agreement on plan, clear channels, timely communication, feedback mechanism, and positive impact. There was a strong positive correlation between identification, participation, communication, monitoring, and project performance. Significant positive correlations suggest that improving these factors may positively impact project performance. The comprehensive analysis of stakeholder dynamics in NGO-supported healthcare projects underscores the multifaceted nature of project success. Stakeholder identification, participation, and monitoring emerge as critical components contributing significantly to project performance. While communication shows a positive correlation, its direct impact may require a better understanding and tailored strategies. NGOs operating in Nairobi City County are encouraged to leverage these findings to refine their stakeholder engagement strategies, emphasizing identification, active participation, and effective monitoring to maximize the positive impact of healthcare projects in the region.