Free and immobilized baker's yeast were successfully employed in the asymmetric hydrogenations of prochiral beta-keto esters and ketones in glycerol. The activities with immobilized cells were always higher then with free cells while the enantio selectivity was very high (99%) with both catalysts. Using glycerol, a non-toxic, biodegradable and recyclable liquid, as an environmentally friendly solvent allowed easy separation of the product by simple extraction with diethyl ether. (c) 2006 Elsevier Ltd. All rights reserved.