An UV spectrophotometric method for the quantitative determination of Diazepam in tablet was developed in present work. The Linearity, Intraday precision, Interday Precision, Ruggedness, limit of detection and limit of quantitation were studied according to International Conference on Harmonization guidelines. UV spectroscopic determination was carried out at an absorption maximum of 266.5 nm using methanol as solvent. The method was found to be linear and obeys beers law in the concentration range 2-20 μg/ml with a correlation coefficient 0.999. The developed method was validated as per ICH guidelines and was found to be accurate and precise. Thus the proposed method can be successfully applied for the estimation of Diazepam in pure and tablet dosage form.