Rasagiline mesylate is a new molecule which acts as irreversible monoamine oxidase inhibitor used for the treatment of idiopathic parkinson’s disease. The aim of present work was to develop a simple, accurate, reproducible and cost effective spectrophotomeric method for determination of Rasagiline mesylate in a pharmaceutical dosage form using phosphate buffer pH 6.8 as a solvent. The drug in solution form showed absorption maxima at 265 nm and obeys Beer’s Lambert’s law in concentration range 100-300 μg/ml. The regression equation was y = 0.003x + 0.0056 and correlation coefficient of (R²) 0.9995. The limit of detection and limit of quantification was found to be 2.915 μg/ml and 8.833 μg/ml. Percent relative standard deviation values for the intra-day and inter-day precision were found to be 0.4308 and 0.6160 respectively. Mean % recovery was 100.45%. The proposed method was successfully applied for determination of Rasagiline mesylate in a tablet dosage form without any interference from common excipients.