Flooding in Bangladesh is a significant and one of the frequent natural hazards, intensified by its geographical location, climate change, and socio-economic factors. Considering, Nature-based Solutions (NbS) in coastal areas like Shyamnagar upazila represent a promising and sustainable alternative to traditional infrastructure-based flood management. This research paper identifies the knowledge gaps associated with the effectiveness and societal implications of nature-based solutions for flood management in the Burigoalini Union, Shyamnagar, Satkhira. The conceptual framework known as the "Knowledge Gap" framework is used to employ focused group discussions among fishermen, farmers, and community members, along with applying thematic analysis through NVivo, to explore the relationship between NbS and society, besides to identify good practice strategies for planning and implementing NbS in flood management within the coastal zone. The findings of this study will contribute valuable knowledge to the understanding of the effectiveness of NbS in Bangladesh, also providing helpful insights for policymakers and practitioners seeking to improve flood resilience and promote sustainable development in coastal Bangladesh.