The results of a study on the fishery, biology, exploitation and mortality of hilsa shad (Hisa ilishu) are presented. The average annual landing of Hilsa ilisha for 1979 - 88 was 5710 tonnes forming 0.4% of the total landings. The major craft and gears and the contributions of different states are presented. Age at first maturity was estimated as 1.98 years. The details of spawning migrations, maturity stages and fecundity are discussed. The total mortality, natural mortality and fishing mortality coefficients were obtained as 1.71,0.704 and 0.9444 respectively. The present yield of4 168 tonnes was the same as the estimated MSY indicating the optimum level of exploitation.