A simple, precise, rapid and specific reversed phase high performance liquid chromatographic method for determination of S (-) Metoprolol Succinate was developed and validated. The chromatographic separation was achieved on Inertsil ODS column (125×4.6mm, 5µ), using a mixture of 20mM potassium dihydrogen phosphate (pH adjusted to 3.5 with ortho-phosphoric acid) and acetonitrile as mobile phase in the ratio of 80:20 at flow rate of 1.5 mL/min. The detection was performed at 220 nm. The calibration curve was linear in the range of 30 - 90 µg/mL (r2 = 0.99999). Major impurities and degradation products were well separated from S(-) Metoprolol Succinate. Thus this assay method can be considered as stability-indicating.