The enantioselective hydrogenation of ethyl pyruvate (EtPy) on Pt-alumina (E 4759) catalyst modified by dihydrocinchonidine (DHCD) at a hydrogen pressure of 1 bar in toluene was studied. The effects of the modifier concentration (0.001-1 mmol l(-1)) and temperature (-10, 0, 24 degreesC) on the reaction rate and the enantioselectivity have been studied. Under mild experimental conditions (hydrogen pressure: 1 bar, temperature: -10 degreesC, DHCD concentration: 0.1 mmol l(-1)) an optical yield of 88% can be achieved. When EtPy hydrogenation was studied in AcOH under identical conditions, it was established that the DHCD/Pt-surf ratio necessary for achieving maximum enantioselectivity is highly solvent dependent: this ratio is 0.007 in AcOH and 0.12 in toluene. This large difference in DHCD/Pt-surf may be a reflection of a difference in reaction mechanism.