Blends of recycled poly(ethylene terephthalate) (R-PET) and high-density polyethylene (R-PE), obtained from post-consumer packaging materials, were prepared both by melt mixing and extrusion processes and compatibilized by addition of various copolymers containing functional reactive groups, such as maleic anhydride, acrylic acid and glycidyl methacrylate. The effect of the type and concentration of compatibilizer, as well as the mixing conditions, on the phase morphology, thermal behaviour, theological and mechanical properties of the blends was investigated. The results indicated that addition (5divided by10 pph) of ethylene-co-glycidyl methacrylate copolymer (E-GMA) allows for a marked improvement of processability and physical/mechanical performances of R-PET/R-PE blends.