Esomeprazole is a proton pump inhibitor drug that is effective to maintain the pH of the stomach. Esomeprazole was formulated as film coated tablet that includes mandatory drug testing bioequivalence according to Regulation Head of National Agency of Drug and Food of the Republic of Indonesia about Mandatory Drug Testing equivalences. Drug bioequivalence trials should use validated bioanalytical method. This research aimed to develop analytical methods esomeprazole in human plasma from optimum chromatographic conditions, the optimum plasma preparation method, until the validation of analytical methods. The optimum chromatographic condition was obtain using C-18 column (Waters, Sunfire™ 5 μm; 250 x 4.6 mm), column temperature 40 °C; mobile phase acetonitrile - phosphate buffer pH 7.6 (40: 60% v/v); a flow rate of 1.00 mL/min; photodiode array detector at a wavelength of 300 nm; and lansoprazole as internal standard. Sample preparation using liquid-liquid extraction with dichloromethane as solvent and then dried with nitrogen gas at a temperature of 40 °C for 30 minutes; and reconstituted with mobile phase of 100 mL. The results of validation fulfilled the acceptance criteria of validation method based on EMEA Bioanalytical Guideline 2011. The method was linear at concentration range of 5.0 to 450.0 ng / mL with r > 0.9997.