Summary: Polyamide 6 (PA6)/multiwall carbon nanotubes (MWCNTs) nanocomposites have been prepared by an extrusion process assisted by ultrasounds. The ultrasounds system has been incorporated at the extrusion die, when the material is flowing through the exit channel. The application of an ultrasound field to a polymer melt has been shown a very efficient method to improve productivity of the process. When ultrasounds are applied, the extrudate flow is highly enhanced maintaining the same processing conditions. In addition, the ultrasounds contribute to the deagglomeration of CNTs into the matrix, as can be conclude from the drop in the electrical resistivity values of the nanocomposites observed when ultrasounds are applied. For the system PA6/MWCNT 7wt%., the electrical resistivity increases three orders of magnitude when ultrasounds are employed during the extrusion. In addition, a high reduction in the electrical percolation index is obtained for nanocomposites extrudated by the assistance of ultrasounds.