Restoration of urban lakes in rapidly developing regions like Coimbatore District, Tamil Nadu, India, holds critical implications for ecological sustainability, water security, and social well-being. This paper presents a comprehensive cost–benefit analysis (CBA) of three major lake restoration initiatives in Coimbatore District, focusing solely on secondary data. The study aims to (1) evaluate the economic, environmental, and social outcomes of restoration for each lake; (2) compare the cost–benefit ratios to identify the most impactful project; and (3) provide methodological insights into CBA application for urban ecological restoration. The research synthesizes global and local CBA best practices, using structured frameworks adapted from established literature. The findings reveal that while financial costs are substantial, the long-term environmental and social benefits far outweigh initial investments, especially when intangible benefits are accounted for. However, significant uncertainties and biases persist in benefit estimation, underscoring the need for robust methodological reforms. The paper concludes with recommendations for policymakers and practitioners on optimizing resource allocation and integrating broader societal values into future restoration planning.\\n\\n