Nanocomposites of PA6 / organoclay at different concentration were prepared via melt intercalation method using a corotating twin screw extruder. The composites were prepared with Brazilian clay that was treated with different modifiers based on quaternary ammonium salts to obtain three types of organoclays. After extrusion the mixtures were injection molded into specimens that were tested to obtain the properties of tensile strength, notched izod impact and heat deflection temperature. The structure and morphology of the nanocomposites were characterized by x-rays diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the modifier “dodigen” which promoted the intermediate expansion of the bentonite clay within the three salts used for the modification of the clay affects more significantly the mechanical properties, HDT and morphology of the polyamide 6 due to the higher level of exfoliation observed in these systems compared to the others modifiers. The improvement of the properties was correlated to the level of exfoliation/intercalation obtained which depends on the process technique used, surface treatment of the Brazilian clays with organic salts and interaction between polymer and clay.