The important key intermediate of quinolone analogue synthesis, (1 S,2 S)-2-fluorocyclopropanecarboxylic acid, was prepared enantioselectively by a microbial resolution. One of the strains with the highest enzymatic specificity was selected from soil and when lyophilized cells were treated with corresponding ester, the remaining (1 S,2 S)-ester was obtained with high enantiomeric purity (98% e.e.).