A simple, precise, accurate and economical UV visible spectrophotometric method has been developed for estimation of Diclofenac sodium drug by AUC method. The standard and sample solutions were prepared by using methanol as a solvent. Quantitative determination of the drug was performed at wavelength range 250-350 nm. The linearity was established over the concentration range of 10, 20, 30, 40&50 µg/ml for Diclofenac sodium with correlation coefficient value of 0.997. Precision studies showed that % relative standard deviation was within range of acceptable limits. The mean percentage recovery was found to be 99.38%. The proposed method has been validated as per ICH guidelines.