A multi-site community-based aquaculture system (C-BAS) initiative was launched across 14 villages in northern Thailand in 2023 to enhance food security and livelihood resilience. A mixed-methods approach combined the Community Aquaculture Viability Index (CAVI), Community Capacity Assessment (CCA) and cost-benefit analysis to evaluate social, technical, economic and environmental dimensions of success. Seven sites were successful: four failed. Moreover, three achieved partial success. Success was strongly correlated with leadership, social cohesion and knowledge gains. At the same time, high feed and fingerling costs, limited market access, and climate stressors such as cold-season mortality and flooding constrained profitability. Although C-BAS improved household protein availability and strengthened local skills, its contribution to stable income remained limited. Overall, the findings indicate that while C-BAS can enhance food security, achieving long-term resilience will require policy support, cooperative models and cost innovations.