The present study was conducted to assess the temporal distribution of ichthyofaunal composition of Basurabad beel in Khulna, Bangladesh and investigated the fish biodiversity and core threats to biodiversity to provide recommendations for conservation in the beel. During the study period, total 33 fish species were recorded belonging to 6 orders. The order wise fish species availability was maximum in Perciformes (39.40%) and minimum in Beloniformis (3%). The value of Shannon-Weaver diversity index was found higher in Fultola (1.19±0.41) and lowest in Basurabad (0.68±0.17) while the maximum value of Margalef richness index found in Basurabad (1.12±0.35) and lowest in Debitola (0.68±0.34). The value of Pielou's evenness index was higher in Boroitola (0.61±0.20) and lowest in Basurabad (0.31±0.16) however the Pielou's index showed an uneven distribution of fish species in the Basurabad sampling point. The value of Simpson dominance index was higher in Fultola (0.58±0.10) and lowest in Kishmath-Fultola (0.39±0.16). Ten different kinds of fishing gears were identified under 5 major groups in the beel. Among all the gears operated, seine net (Jagat Ber Jal) had the highest catch 31.3±4.1 CC/haul/day/gear (kg) followed by current jal 10.5±2.5 CC/haul/day/gear (kg). This study suggests that comprehensive studies on fisheries biology including reproductive biology, growth, stock assessment and their association with existing laws are essential for the sustainable management and conservation of fish species in the Basurabad beel.