The biology and population dynamics of Secutor insidiator from the trawling grounds off Kakinada were studied. The estimated length at first maturity is 90 mm and the spawning season is protracted with a peak during January-March period. The von Bertalanffy parameters of growth in length are estimated as L_∞-123 mm, K=1.2 per year and t_o=0.01 year. The estimated lengths on the completion of first and second years are 86 and 112 mm respectively. The length-weight relationship can be described by the equation: log W(g) = —5.73713 +3.43654 log L (mm). The instantaneous rate of total mortality during the period is estimated as 6.1 and the values of natural mortality rate, by different methods, are estimated as ranging from 1.8 to 2.6. Length and age at first capture are 80 mm and 0.87 year respectively. Under the present value of t_c, yield increases with increased F without reaching a maximum; highest yield, however, can be obtained at t_c ranging from 0.5 to 0.7 with the present Z and different value of M considered.