The aim of the present study is to develop a high resolved and validated liquid chromatography method for the separation and quantification of pimozide and its related impurity A and B in bulk and pharmaceutical formulations. Separation of impurities and pimozide was achieved on Spherisorb ODS2 column (250mm x 4.6mm, 5μ) using mobile phase composition of methanol, acetonitrile and 0.1M sodium perchlorate in the ratio of 40:30:30 (v/v) at pH 6.1 as mobile phase at a flow rate of 0.8ml/min in isocratic condition. UV detection of the eluents was monitored at a wavelength of 240nm. Well resolved peaks were observed at a retention time of 7.0, 5.9 and 10.1 min for pimozide, Impurity A and B respectively. Calibration curve was plotted in the concentration range of 75-450 µg/ml for pimozide and 1-6µg/ml for impurity A and B with limit of detection of 2.4µg/mL, 0.016µg/mL and 0.025µg/mL for pimozide, impurity A and B respectively. Forced degradation study confirmed that the method can separate the known and unknown impurities of pimozide and the % degradation was found to be very less in all stress conditions. The method is suitable for identification and quantification of impurities A and B along with pimozide in bulk drug and formulations. © 2021 Elsevier B.V., All rights reserved.