An approach for Simultaneous estimation of Paliperidone in formulation in presence of its degradation products. The method has shown adequate separation for Paliperidone from their associated main impurities and their degradation products. Separation was achieved on a Zorbax SB C-18, 50 mm x 4.6 mm, 1.8 µm (Agilent) column at 50°C temperature by using a mobile phase A consisting Buffer (pH 4.0) – Acetonitrile (95:5 v/v ) [Buffer: 0.05M Na2HPO4 anhydrous and Ortho phosphoric acid] and Mobile phase B at a flow rate of 1.4 ml/min, and UV detection at 238 nm. In the present study, comprehensive stress testing of Paliperidone was carried out according to ICH guideline Q1A (R2). The specificity of the method was determined by assessing interference from the placebo and by stress testing of the drug (forced degradation). Drug was subjected to Acid hydrolysis, Alkali hydrolysis, Oxidation, Dry heat and Photolysis to apply stress conditions. There were no other coeluting, interfering peaks from excipients, impurities, or degradation products due to variable stress conditions, and the method is specific for determination of Paliperidone in the presence of degradation products. The method was validated in terms of linearity, precision, accuracy, specificity, robustness and solution stability. The linearity of the proposed method was investigated in the range of 30-90 µg/ml (r2 = 0.9995) for Paliperidone. Degradation products produced as a result of stress studies did not interfere in the estimation of Paliperidone and the assay can thus be considered stability-indicating.