A stability indicating RP-HPLC method was developed to quantitatively measure Venlafaxine in both its pure form and pharmaceutical formulations, following ICH guidelines for validation. The method employed an Inertial ODS C18 column (150mm x 4.6mm, 5µ) at ambient temperature (30°C) with a flow rate of 0.8 ml/minute using isocratic elution. UV detection at 232 nm was performed following injection of 20 µl of the sample. The mobile phase, consisting of phosphate buffer and acetonitrile (30:70, v/v), also served as the diluent. The retention time for Venlafaxine standard was determined to be 5.011 minutes. The method demonstrated linearity over a concentration range of 12.5-75 µg/ml, with a correlation coefficient of 1. Precision and accuracy studies indicated % RSD values below 2. This validated method is suitable for routine assay determination of Venlafaxine in both its pure form and pharmaceutical formulations.