Diethyl l-tartrate (DET) is used as a biobased plasticizer for poly(lactide) (PLA) formulations with improved ductile properties without compromising biodegradation. Different weight percentages (wt.%) of DET in the 0–50 wt.% range are added to PLA by melt compounding and subsequently processed injection molding. The effect on mechanical, thermal, thermo-mechanical, morphology, biodegradation, ...