Poly(lactic acid) (PLA) is well known as a biocompatible, bioresorbable, and biodegradable polymer superior to petrochemical polymers from the standpoint of total energy consumption and life-cycle CO2 emission, since it can be obtained from natural sources. However, the brittleness of PLA is a big drawback for its wide application. Although many studies have been carried out modifying PLA, there is very limited work on reactive blending of PLA. This study demonstrates a dramatic improvement in the mechanical characteristics of PLA by its reactive blending with poly(ethylene-glycidyl methacrylate) (EGMA). It is shown that the interfacial reaction between the component polymers contributes to the formation of super-tough PLA materials, superior to benchmark acrylonitrile-butadiene-styrene (ABS) resins. The novel material highlights the importance of interface control in the preparation of multicomponent materials. (C) 2008 Elsevier Ltd. All rights reserved.