A low cost precise spectrophotometric method has been developed for the estimation of Zanamvir in bulk and tablet dosage form. Zanamvir shows maximum absorbance at 260nm in presence of Double Distilled Water and phosphate buffer of pH 7.4. The Beer’s law is obeyed in the concentration range of 2-10 μg/ mL for this drug. The graph of the drug shows a straight line with correlation coefficient of 0 .9999. The assay method of the drug was validated by accuracy and precision of the proposed method. The results are validated as per the directions of International conference on Harmonization.