Magnetic nanoreactors based on Pd nanoparticles supported on magnetic carbon nanotubes that are coated by a mesoporous silica layer, (Fe3O4-CNT-Pd)@m-SiO2, have been selectively synthesized by facile steps. The prepared system exhibits high catalytic efficiency in Suzuki-coupling reactions because of the Pd nanoparticles supported on carbon nanotubes (CNT-Pd). Most importantly, induced magnetic properties make the separation of the catalyst easy from the reaction media, which can be re-used several times with significant activity. Moreover, the existence of a mesoporous silica layer makes the Pd catalyst very stable and does not allow the Pd nanoparticles to get detached from the CNT supports. The above-mentioned observations make the obtained catalyst a great candidate for future applications.