This paper presents the preparation and characterization of MWCNT-Multi-Walled Carbon Nano-Tube/epoxy nanocomposites, as materials with a good yield for shielding electromagnetic interferences-EMI. Both the precursors used, and the nanocomposites obtained were characterized by different techniques: FTIR-Fourier transform infrared spectroscopy, Raman spectroscopy, SEM-Scanning Electron Microscope and XRD-X-ray diffraction. The electrical and mechanical properties of the nanocomposites were estimated compared to the epoxy resin without addition. Electromagnetic interference shielding tests were conducted in the 2.5-6.4 GHz frequency band. The results were found to be promising since for the MWCNT/epoxy sample it was obtained a 20 dB attenuation when compared with the ambient air.