This study was conducted to investigate the effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. Among the investigated addition orders, the best sequence of component addition (PI-C i.e. PET, Impact Modifier-Clay) was the one in which poly (ethylene terephthalate) was first compounded with E-MA-GMA. Later, this mixture was compounded with the organoclay in the subsequent run. In X-ray diffraction analysis, extensive layer separation associated with delamination of the original clay structure was observed in PI-C and (CI-P i.e. Clay, Impact Modifier-PET) sequences with both 1 and 3 wt. % clay contents. X-ray diffraction patterns showed that, at these conditions, exfoliated structures were obtained.