A 45-month community-based suicide prevention program was launched in response to the emergence of a suicide cluster in 2010 in Hong Kong. This study aimed to evaluate the effectiveness of the program, document the implementation and outcomes of the project, and identify factors that contribute to the outcomes. The program was delivered following the five key components of the public health approach: (a) community consensus building; (b) surveillance and monitoring; (c) development of coordinated action strategies; (d) interventions development and implementation at the universal, selective, and indicated levels; and (d) program evaluation. A significant decreasing trend of suicide was found in the study site during the intervention period, whereas no changes were found in the three control sites. Spatial analysis also showed that the suicide cluster subsided after the intervention. Three impacts and one challenge of the program were identified from the qualitative feedback of the program stakeholders. More investigations should be made to assess the sustainability of this community-based suicide prevention effort in the long run. A community-based suicide prevention program was successfully implemented to address the suicide cluster. A reduction in the suicide rate was observed after the intervention.