A thermostable esterase from the hyperthermophilic archaeon Sulfolobus solfataricus was partially purified 590-fold with 16.2% recovery. The partially purified esterase had a specific activity of 29.5 μmol min mg when the enzyme activity was determined using p-nitrophenyl butyrate as a substrate. The apparent molecular weight was about 100 kDa, while the optimum temperature and pH for esterase were 75°C and 8.0, respectively. The enzyme showed high thermal stability and solvent tolerance in comparison to its mesophilic counterpart. The enzyme also showed chiral resolution activity for (S)-ibuprofen, indicating that S. solfataricus esterase can be used for the production of commercially important chiral drugs.