This study assesses the current status of fish biodiversity in the Bhairab River, Jessore, Bangladesh, and identifies conservation measures. Conducted from May to August 2016, the research involved surveys, interviews with 50 fishers, and community discussions, revealing a total of 39 fish species and significant biodiversity loss due to overfishing, pollution, and habitat degradation. Recommendations for conservation include community-based management, pollution control, and legal measures to protect fish biodiversity.