Microwave heating was used to prepare poly(ethylene-co-vinyl acetate) (EVA)/clay nanocomposites by solution intercalation. The effects of nanocomposite preparation conditions, such as temperature, irradiation time and clay concentration on the morphology and gas transport properties of EVA membranes were investigated. The microwave irradiation temperature and time did not have any effect on the filler distribution and consequently the oxygen permeability of nanocomposites was mainly dependent on the clay content. The oxygen permeability of EVA was reduced by 55% using microwave intercalation of 10 wt.% of clay. Similar reductions were obtained using traditional heating, suggesting that, at least in this work, microwave heating does not improve clay dispersion. (C) 2011 Elsevier B.V. All rights reserved.