A rapid, specific, sensitive high-performance liquid chromatographic method has been developed for determination of Metoprolol Succinate and Hydrochlorothiazide impurities and its degradation products in pharmaceuticals preparation. HPLC was performed on a C18 column with “mobile phase A” consisting of 95:5 v/v of pH 2.5 buffer solution and methanol; while “mobile phase B” consisted of 55:45 v/v methanol and acetonitrile. The mobile phase was pumped in a gradient manner at the flow-rate of 1.0 mL min−1. Ultraviolet detection was performed at 225 nm. Metoprolol Succinate and Hydrochlorothiazide impurities and degradation products along with process impurities were chromatographed with a total run time of 60 minutes. Calibration showed that response of impurities was a linear function of concentration over the range LOQ to 300% of the target concentration (r 2 ≥ 0.999) and the method was validated over this range for precision, accuracy, linearity and specificity. For precision study, percentage relative standard deviation of each impurity was <15% (n = 6). The method was found to be precise, accurate, linear and specific. The method was successfully employed for estimation of Metoprolol Succinate and Hydrochlorothiazide impurities and its degradation products in commercial available capsules and in-house developed formulations.