The present study addressed the reproductive biology of white grunter (Pomadasys hasta) on the South-West coast of Bangladesh. A total number of 59 fish samples were collected once monthly from august 2019 till July 2020. The highest mean value of the gonado-somatic index (GSI) was recorded in December (10.95±2.2), whereas the lowest was in June (0.58±0.24%), with an average value of 4.179±4.402. The fecundity range of fish individuals was 102086-3507692, and the average fecundity was at its maximum (1913454.4±139910) in December. The minimum length of the youngest mature female was 20.38 cm. An increase was recorded in the fecundity associated with the rise of total length, body weight, and gonad weight, showing a significant linear relationship. In contrast, length-weight relationship (R²=0.8653) was non-linear, positively correlated, showing negative allometric growth (b=2.497). Additionally, gonadal histology displayed seven stages of oocyte development. Early perinuclear and late yolk granule stages were detected in October and December, respectively. Based on the GSI, fecundity, and gonadal histology, the breeding season of P. hasta was recorded from October to January, recording a remarked peak in December. This study would assist in the development of induced breeding techniques and provide enriched data for the sustainable management of this population in an open ecosystem.