Different ways of synthesizing poly(lactic acid) are reviewed. Emphasis is placed on the development of various catalysts for the ring-opening polymerization of lactide, which has become the most common way to access high molecular weight poly(lactic acid). To complement a survey of the best catalysts for this reaction, we discuss the different mechanisms by which these complexes catalyze the ring-opening polymerization of lactide. The chapter concludes with a description of the methods used for stereoselective polymerization of lactide. [ABSTRACT FROM AUTHOR]