Lipase-catalyzed ring-opening polymerization of 10-fluorodecan-9-olide (la), 11-fluoroundecan-10-olide (Ib), 12-fluorododecan-11-olide (Ic) and 14-fluorotetradecan-13-olide (Id) gave optically active products with M-w of 3.000 to 8.000, while 10-fluoroundecan-11-olide (3a) gave an optically inactive polymer with M-w = 11.000. On the other hand, Candida antarctica lipase-catalyzed polymerization of 10- to 14-membered omega-fluoro-(omega-1)-hydroxyalcanoic acids gave optically inactive oligomers with M-w of 3.000 to 11.000 in the presence of molecular sieves, while reactions without molecular sieves gave oligomers with lower molecular weight, but with small optical rotations. 9-Fluoro-10-hydroxydecanoic acid, on the other hand, gave an optically inactive polyester with M-w = 7400.