This paper deals with the development and validation of stability indicating an isocratic high performance liquid chromatographic method for the quantitative determination of memantine hydrochloride. The method is simple, highly sensitive, selective and is capable of quantitative determination of memantine hydrochloride. The chromatographic separation is achieved by injecting 20µL standard solution of memantine hydrochloride into HPLC system with refractive index detector using a YMC ODS-AQ, 5µm (150 x4.6)mm column. The mobile phase consists of 10 mL Triethylamine in 1L water(pH 5.5 adjusted with glacial acetic acid):MeOH in the ratio of  40:60 v/v. The flow rate was set at 0.9 ml/min with column and cell temperatures at 40˚C and 50 ˚C respectively and runtime was optimized to 10 min. Forced degradation studies were performed on bulk sample of memantine hydrochloride using acid (5.0Nhydrochloric acid) ,alkali (1.0N sodium hydroxide),oxidation (30% hydrogen peroxide),thermal(105 ˚C),photolytic and humidity conditions. The peak purity was checked with LC-MS and LC-MS/MS. The developed LC method was validated with respect to specificity, precision, linearity, ruggedness, stability of analytical solution and robustness.