A simple and fast flow injection spectrophotometric method for the determination of bromate in water samples was developed. The detection system is based on the oxidation of prochlorperazine (PCP) with bromate in strongly acidic medium. Large amounts of chloride and bromide was found, for the first time, to act as an activator, and to enhance the sensitivity for bromate detection. The oxidation product of PCP gives pink color, which can be used to monitor the reaction spectrophotometrically at 525nm. Under the optimal conditions, the method is selective; only nitrite, chlorite and hypochlorite can interfere with the determination of bromate. The elimination of these three ions is discussed. The calibration graph for bromate determination was linear in the range of 10–130μgL −1 with a detection limit of 2.3μgL −1 . The repeatability was satisfactory, with the relative standard deviation of 1.1% (25μgL −1 , n=10). The sample throughput was 44h −1 . The proposed method was found to be highly reliable for screening drinking waters containing bromate, which is above or below legislation limit of 10μgL −1 .