The preparation of halohydrin β-blocker precursors using yeast-catalysed reduction of α- haloketones was performed. The influence in the yield and ee of several process variables was analysed. The (S)-enantioselectivity observed with Saccharomyces cerevisiae can be changed to (R)-enantioselectivity using methyl vinyl ketone as selective inhibitor (25 mM). Using resting fresh cells better yields and ees are observed than using growing cells. ...