A simple method has been developed for decorating multi wall carbon nanotubes (MWCNTs) with palladium and silver nanoparticles. In this method, MWCNT was opened and functionalized using nitric and sulfuric acid mixture. Then citric acid was polymerized in the presence of functionalized MWCNT and MWCNT-graft-poly (citric acid) (MWCNT-g-PCA) was obtained. The mixing of MWCNT-g-PCA with metal salts, such as palladium chloride and silver nitrate, leads to encapsulation of metal nanoparticles in the polymeric shell (MWCNT/Pd, AgNPs). The structure of MWCNT/Pd and AgNPs were characterized by usual spectroscopy and microscopy methods. The influence of nanoparticles on the electrical conductivity of MWCNT was also investigated.