Over the last decade, there has been an increasing interest in lipase/esterase-catalyzed polycondensation as an alternative to metal-based catalytic process, because the former can proceed under mild reaction conditions and does not cause undesirable side reactions or produce trace metallic residues. In this review, the in vitro synthesis of aliphatic polyesters by polycondensation using lipases or esterases is systematically summarized, especially for the synthesis of complex and well-defined polyesters. The polycondensation of diols with diacids or their activated esters, including alkyl, haloalkyl and vinyl esters, through esterification and transesterification polycondensation reactions is discussed. In addition, three or more monomers can also be polymerized simultaneously, which provides a new route for preparing functional polymers. Self-polycondensation with respect to hydroxyl and mercapto acids or their esters is another reaction mode discussed in the review. Finally, concurrent enzymatic ring-opening polymerization and polycondensation has been developed to construct novel polyesters with tailor-made structures and properties. Overall, the review demonstrates that lipase/esterase-catalyzed synthesis of polyesters via polycondensation provides an effective platform for conducting "eco-friendly polymer chemistry". Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.