Butis butis is one of the economically valuable fish species in the Mekong Delta, Vietnam. This study provided data on otoliths and their relationship with morphological indices. Seven hundred fifteen individuals were used in this study. These individuals were collected from four sites from Tra Vinh to Ca Mau for six months, from March to August 2019. The otoliths of this fish were oval. The weight of the left otolith was equal to that of the right otolith. However, the length and width of the right otolith were more significant than that of the left otolith. Besides the size and weight of otoliths, this fish also varied by sex, season and location. The weight of otoliths could be considered a parameter to evaluate fish growth because it displayed a close relationship with the fish weight, total length, body height, and head length (r²≥0.6).