This study assessed the applicability of sustainability principles in community development projects in Tanzania, focusing on selected initiatives under the Child Reach Program. The research was guided by the need to understand the extent to which sustainability principles such as community participation, government involvement, capacity building, local ownership, continuous monitoring, and integration into local plans are effectively applied in community projects. A total of 30 respondents who were former stakeholders in four key projects participated in the study. Data were collected using a structured interview. The findings revealed that a majority (53.33%) of stakeholders perceived their projects as sustainable, while 13.33% rated them as very sustainable. The study identified key strategies that promoted sustainability, including early community engagement, government support, skills development, establishment of local management structures, and feedback mechanisms. However, several barriers threatened the long-term success of these projects, such as political divisions within communities, lack of cooperation from parents, integration challenges within school programs, limited inclusiveness, and negative perceptions toward persons with disabilities. The study concludes that while sustainability principles are recognized and applied to a significant extent, socio-political, institutional, and cultural factors limit their full realization. The study recommends the need for inclusive stakeholder engagement, strengthened capacity development, and deliberate efforts to address contextual barriers to enhance the sustainability of community development projects in Tanzania.