(Nano)composites based on ethylene amyl acetate copolymers (EVA) and montmorillonite modified by various alkylammonium cations were processed by mechanical kneading. Polymer intercalation and filler exfoliation were evidenced by X-ray diffraction and transmission electron microscopy, respectively. Nano-composites tensile properties showed that Young's modulus increases significantly even at very low content of the organo-modified filler while preserving high ultimate elongation and tensile stress. The matrix thermal stability an air was increased by 40 degreesC and, interestingly, the obtained nanocomposites present flame retardant properties.