Abstract: Based on the fluorescence quenching effect produced by oxidation of acridine orange with BrO3- in the presence of KBr in a HCl medium, a method for the determination of trace amount of BrO3- in drinking water was proposed. Linear relationship between magnitude of decrease in fluorescence intensity (ΔF) and mass concentration of BrO3- was kept in the range of 10.0-560.0 μg·L-1, when measured at (λex) 493 nm and (λem) 528 nm. Value of detection limit (3S/N) found was 3.03 μg·L-1. The proposed method was applied to the determination of bromate in purified water and barreled water, giving values of recovery by standard addition method in the range of 94.0%-107%.