This paper illustrates a kinetic investigation of esterification reaction involving butyric acid and methanol over amberlyst-15 catalyst. The catalytic reactions were performed in an isothermal well stirred batch reactor using excess of alcohol to prevent the reverse reaction. The experimental parameters studied were reaction temperature, molar ratios of reactants, catalyst loading, stirring speed, initial water present and quantity of molecular sieves added. The optimum reaction conditions for the ester synthesis were found at temperature 343 K, alcohol to acid ratio 3, stirrer speed 300 rpm, catalyst loading of 6.5 % (w/w basis) and molecular sieves 8.5 %. Addition of water to reactor contents has negative effect as expected. Conversion increased with temperature and catalyst loading whereas it decreased as the molar ratio of alcohol to acid increased beyond 3. Molecular sieves added adsorb water formed in the reaction hence favoring reaction in forward direction. Kinetic data was tested for pseudo-homogeneous model, Langmuir-Hinshelwood model and Eley-Rideal model. Studies show that dual site LHHW with reactants and products adsorbing on catalyst surface is most suited for the experimental data.