A simple, rapid and sensitive RP-HPLC method was developed by trail and error and validated for estimation of Atomoxetine HCl in bulk and tablet dosage form. Chromatography was carried out by using pre packed Luna C18,?(250 x 4.6mm) phenomenex column as a stationary phase with mobile phase containing a mixture of 0.1% Triethylamine (pH-3.5)adjusted with OPA:acetonitrile in the ratio of 50:50v/v. The flow rate was 1ml/min.The effluent was monitered at 271nm and retention time of drug is 3.0mins.calibraton curve was plotted with the range of 2-12?g/ml for atomoxetine HCl and the correlation coefficient was found to be 0.999. The percentage values for all the parameters was found to be not more than 2 for RP-HPLC . Validation studies revealed that method is specific, rapid, reliable and reproducible. The high recovery and low relative standard deviation and relative standard deviation confirm the suitability of the method for routine determination of Atomoxetine HCl in bulk and tablet dosage form. The developed method used for routine analysis of Atomoxetine HCl in pharmaceutical dosage form and method is developed and validated as per ICH guidelines.