Novatein®, a protein-based thermoplastic, was blended with poly(lactic acid) (PLA) using reactive extrusion to produce a cheap and degradable material with improved mechanical properties over neat Novatein. Various compositions of Novatein/PLA were prepared with and without a compatibilizer, PLA grafted with itaconic anhydride (PLA-g-IA). Novatein had a tensile strength of 17.4 MPa while a blend of Novatein with PLA-g-IA at 50 wt. % loading increased the tensile strength to 34.4 MPa. All Novatein and PLA-g-IA blends showed an improvement in elongation at break (i.e. from 0.74 to 1.88 at 50-50 composition). Scanning electron microscopy revealed that adding compatibilizer reduced the presence of cracks and voids in fracture surfaces, resulting in a more homogenous microstructure. In the 50/50 blend, the Novatein phase became finer and more evenly dispersed within the PLA matrix. The broad tan δ peak for compatibilized blends decreased in dynamic mechanical analysis of the 50/50 and 30/70 blends due to higher interfacial interaction between Novatein and PLA. Novatein is a hydrophilic polymer and absorbs 50 wt. % of water in just 24 hours, but blending with PLA reduced water absorption to less than 20 wt. %. Blending Novatein with PLA can widen its use in many agricultural and packaging applications, but require itaconic anhydride as compatibilizer.