n-octyl oleate, an aliphatic ester with lubricant properties, was produced by enzymatic esterification reaction of oleic acid and n-octanol. In this study, immobilized lipase from Thermomyces lanuginosus (TLL) via interfacial adsorption on polymetacrylate particles (PMA) was tested as potential biocatalyst. Under optimal conditions, maximum conversion percentage of 95.1 ± 1.3% was observed after 60 min of reaction performed in an orbital shaker under continuous agitation (240 rpm) at 45°C, 10% m/v of biocatalyst using molar ratio oleic acid:n-octanol of 1:1.5 (1800:2700 mM) in a solvent-free system. The biocatalyst did not lose its catalytic activity after twelve cycles of esterification reaction. The product was confirmed by attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopy analysis and their physico-chemical properties were determined according to ASTM standard methods.