Polyolefin/clay nanocomposites were fabricated by directly melt compounding poly(ethylene-co-ran-acrylic acid), PEAA, with sodium montmorillonite and a low molecular weight quaternary ammonium salt in a simple process where all the components were fed simultaneously to the extruder. The effects of processing conditions, salt structure, and concentration on the clay dispersion, morphology, and mechanical properties were investigated using X-ray diffraction, transmission electron microscopy, and dynamic mechanical testing. The one-step method was effective at simultaneously dispersing and intercalating/exfoliating the natural montmorillonite and produced nanocomposites comparable to those prepared by melt compounding the PEAA with commercial organoclay.