Isocratic RP-HPLC method was developed and validated for the analysis of clopidogrel bisulfate counterfeited with acetyl salicylic acid and applied for the determination of clopidogrel bisulfate in pharmaceutical dosage forms. Clopidogrel bisulfate is commonly counterfeited with acetyl salicylic acid and it is not labeled to contain acetyl salicylic acid due to their similar pharmacological effect in inhibiting platelet aggregation. The mobile phase was composed of potassium dihydrogen phosphate buffer 0.02M (pH 2.8) and methanol 30:70 (v/v). The flow rate was 1.5mL/min. Diode array detector was set at 220 nm. The linearity ranges were 10-70 µg/mL and 6-50 µg/mL for clopidogrel bisulfate and acetyl salicylic acid, respectively. The retention time was 2.5 min and 10.23 min for clopidogrel bisulfate and acetyl salicylic acid, respectively. The method was validated according to ICH guidelines. The developed method was successfully applied for the determination of clopidogrel bisulfate counterfeited with acetyl salicylic acid as well as estimation of clopidogrel bisulfate in its different dosage forms.