Abstract: Because of environmental problems, the development of biodegradable polymers has been an area of current research interest. Polylactide as green and eco-friendly polymer still requires improvement of its thermal and mechanical properties for wider and specic applications. Stereocomplex polylactide and nanocomposites are the possible options to improve polylactide properties. This chapter reports the development of high-performance polylactide through stereocomplex and nanocomposite approaches. Stereocomplex polylactide has been developed through a conventional method (solution and melt process), and also by supercritical uid methods. Properties improvement by stereocomplex crystalline remains another limitation in the melt stability. This limitation can be solved by addition of exible fragment in the polylactide chains and star-shaped structures. Nanocomposite is another approach in polylactide properties enhancement by addition of various nanoparticles. Miscibility of the nanoparticles with polylactide chains is the important factor for nanocomposite that can be improved by surface modication and grafting of nanoparticles. Nanocomposite can also be proceeded through solution, melt and supercritical processes. The stereocomplex and nanocomposite approaches can be combined for improving polylactide properties. This approach is named as stereocomplex-nanocomposite polylactide.