The enantioselective esterification of ibuprofen catalyzed by a novel thermophilic esterase (APE1547) from the archaeon Aeropyrum pernix K1 was successfully conducted in organic solvents. The effects of acyl acceptor, substrate ratio, organic solvent, temperature, and water activity were investigated. Under optimum conditions, the highest enantioselectivity (E = 38.1) was obtained with a higher enzyme activity (216.5 ${mu}mol/g/h$). Celites were added into the reaction mixture to remove the water produced in the esterification. The reaction achieved its equilibrium in approximately 96 h with a conversion of 57 and 99% (ee) of the un-reacted (S)-ibuprofen obtained.