The structural and electrical properties of carbon nanotubes (CNTs) of different types (SWCNT, DWCNT and MWCNT) / poly-methyl methacrylate (PMMA) composites films have been investigated. The composite were prepared in the form of films by the solution casting technique. Their structural properties were investigated by X-ray diffraction (XRD). XRD revealed that CNTs are well immersed in the polymer chains. The dc electrical conductivity measurements of CNTs/PMMA films show that there is one order of magnitude enhancement relative to plain PMMA fi