Enzyme-catalyzed synthesis of methyl benzoate is reported. It is the first example of direct esterification of benzoic acid which provides good yields. The reaction was performed in a heterogeneous medium by Candida rugosa lipase powder suspended in a hexane/toluene mixture. the impact of some factors was examined. Bonzoic acid does not inhibit the lipase until 100 mM. Above 90 mM, methanol mainly interacts with the water absorbed on the biocatalyst. A minimum water must be provided propotionally to the lipase content. Toluene, necessary for benzoic acid solubilization, also acts negatively on reaction kinetics. This is attributed the biocatalytic and the organic phases.