This study supplies knowledge on the reproductive traits of Glossogobius aureus, one of the commercial fishes living in brackish water and freshwater. A collection of 742 G. aureus specimens was caught using gill nets from January to December 2020. The results of the gonadal breeding frequency and gonadosomatic indices showed that G. aureus spawned year-round, but with higher activity during four months, from August to October, of the wet season. Size at first maturity (Lm) of males was higher than that of females in all study sites. The batch fecundity (F) was 1044–27,349 eggs/female and increased with fish size, as shown by the high determination values (r 2 > 0.6). The study results provide new references on the reproductive biology of the population of Glossogobius aureus which will help in the sustainable management of its fisheries in the studied areas.