Abstract The influence of the amount of SO42−/La2O3 (2–20%) over structural and catalytic properties of HZSM-5 was evaluated. The catalysts were characterized by thermogravimetric analysis, X-ray diffraction, adsorption/desorption of N2 and infrared spectroscopy and they were tested in the esterification reaction of oleic acid and methanol. The influence of the amount of catalyst (2, 5 and 10%) and the influence of molar ratio oleic acid:methanol (1:10, 1:20 and 1:45) were evaluated. The characterization analyses indicated that the starting material had not significant structural and textural changes, but the acidity had changes. The most expressive results of conversion were obtained in the molar ratio 1:10 and 5% of catalyst. The most efficient catalyst was that modified with 10% of SO42−/La2O3 (10OLS/HZ), which presented maximum conversion (100%). In general, the catalysts were efficient. It was possible to observe that most of the modifications produced catalysts more active than the starting material.