A series of nanocomposites prepared by melt-blending of Cloisite organoclays with ethylene-co-vinyl acetate (EVA) and ethylene-co-methyl acrylate (EMA) copolymers were investigated by using small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and rheological techniques. SAXS and TEM results confirmed mixed clay intercalation and exfoliation in all tested nanocomposites. The melting temperature, Tm, and crystalline structure (orthorhombic) in EMA and EVA were not significantly affected by the presence of organoclays, indicating that the clay particles were predominantly confined to the amorphous phase. Rheological properties above Tm were very similar in EVA and EMA nanocomposites. Both systems exhibited pseudo-solid rheological behavior in small-strain oscillatory shear experiments, yet they could yield and flow under a steady shear, which is characteristic of physical gelation. The pseudo-solid rheological beha...