The present study addresses the crucial sustainability concerns in small-scale fisheries (SSF) against the backdrop of escalating anthropogenic activities and climate change impacts on marine fishery and ecosystems. Our study focused on a traditional fishery exploitation area spanning 12,646.12 km2 along the Southwestern Coast of Kerala, India, and explored four widely used fishing gears. We established an integrated decision-making VIKOR framework, and preferential modelling by incorporating techno-economic and environmental aspects to draw the optimal solutions. Leveraging 10 sustainability indicators, the boat seine emerged as the most sustainable gear, showcasing significant profitability (US$ 16,126/year−1 net profit) and remarkable energy efficiency, surpassing gillnetters, longliners, and shore seiners by 8.4, 4.9, and 3.0 times, respectively. The Fuel Use Intensity (FUI) and CO2 emissions analysis (F value = 58.37, P < 0.0001) emphasizes the ecological implications. The developed VIKOR sustainability index, introduced in this study, effectively assesses gear efficiency and sustainability. Further, the study revealed that gear selectivity, technical specifications, and operational trajectories considerably influence the index dynamics. This research aligns with the global commitment to the Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries (SSF Guidelines) and contributes scientifically to Sustainable Development Goals (SDGs). By bridging empirical rigor with international frameworks, the study could aid in sustainable fisheries management and environmental stewardship, deemed essential for the global pursuit of ecological, economic, and social sustainability in small-scale fisheries.