A simple, economical, rapid, accurate, precise spectrophotometric method has been developed and validated according to ICH Guidlines for the Mirabegron as active pharmaceutical ingredient (API) by UV spectrophotometric method. The absorption maxima of Mirabegron was found to be at 249 nm wavelength using 1N Hcl as a solvent. Linearity range was found to be 3-15μg/ml, with the correlation coefficient being more than 0.999. The relative standard deviation was found to be < 2%. The percentage recovery was within the range of 98% -105%, indicating that there is no significant interference from the other ingredients present in the formulation. The method can be applied for the routine analysis of Mirabegron as API in pharmaceutical preparation.