This paper was aimed to evaluate the effects of matrix types (with or without ethylene-glycidyl methacrylate compatibilizer) and rice husk (RH) loadings (40-80 wt.%) on RH-reinforced recycled high-density polyethylene/recycled polyethylene terephthalate (rHDPE/rPET) ecocomposites. Results showed that the thermal stability and flammability resistance properties increased as the RH loadings increased. The addition of RH has effectively delayed the thermo-oxidation process of rHDPE/rPET matrix by 10 degrees C, and evident flame retardant effect has also been observed (decreased burning rate up to 24% in comparison to neat polymer blend). It is interesting to note that compatibilization of polymer blend matrix has further increased the thermal stability of ecocomposites. SEM images confirmed the enhanced interfacial bonding of phases in the compatibilized matrix ecocomposites. It can be concluded from this study that the used agro-waste material (RH) is attractive reinforcements in recycled plastics from the standpoint of their thermal and flammability properties. (C) 2016 Elsevier B.V. All rights reserved.