A simple, specific, precise, and efficient method for the simultaneous estimation of Atorvastatin and Ezetimibe in pure and pharmaceutical dosage forms by a Reverse Phase - High Performance Liquid Chromatography method is developed and validated. Selected mobile phase was in a combination of Methanol and Phosphate buffer (pH - 3.8) (40:60 % v/v). Optimized column is a Phenomenex Gemini C18 (4.6 mm × 250 mm) 5 µm particle size and at a flow rate of 1.0 ml/min with detection wavelength at 251 nm for Atorvastatin and Ezetimibe. In our study, the validation of analytical method for determination of Atorvastatin and Ezetimibe in pure and pharmaceutical dosage forms was performed in accordance with the parameters including - system suitability, specificity, linearity of response, accuracy, precision (reproducibility & repeatability), robustness (change of wave length ± 2 nm). The method is validated according to ICH guidelines. The results obtained by RP - HPLC method are rapid, accurate and precise. Therefore, proposed method can be used for routine analysis of Atorvastatin and Ezetimibe in the pure form as well as in combined pharmaceutical dosage form.