A Simple and rapid reverse phase high performance liquid chromatography (RP-HPLC) method was developed and validated for quantitative determination of blonanserin in bulk drug samples and formulations. Blonanserin was analysed by using column (Phenomanex Luna C18 , 4.6 mm × 25 cm, 5 microns), with mobile phase consisting of water : acetonitrile : TFA (65:35:0.05 v/v). The flow rate was set 1.0 mL/min and and analysis was performed at wavelength 237 nm using Photo Diode Array (PDA) detector at ambient temperature. The method was validated. The retention time for blonanserin was around 4.9 minutes. The calibration curves were linear (r≥0.9996) over a concentration range from 10.0 to 150.0 μg/mL. Limit of detection (LOD) and Limit of quantitation (LOQ) were 5.08 μg/mL and 15.39 μg/mL respectively. The developed method was successfully applied to estimate the amount of blonanserin in tablet formulations