In present work, wall-to-wall joining of two parallel multiwalled carbon nanotubes (MWCNTs) has been successfully demonstrated using electron beam inside high resolution transmission electron microscope. The used MWCNTs have been grown using cobaltocene and benzene as catalyst and carbon precursor, respectively via thermal CVD technique. We have proposed that in present case, irradiation induced joining is achieved if adequate balance between sputtered carbon atoms from the outer walls of MWCNTs and generation as well as migration of defects along the tube axis is obtained. Casimir effect is not found to play dominating role in the joining process. The proposed method can potentially be used for developing wall-to-wall interconnection between MWCNTs using electron beam. (C) 2018 Elsevier B.V. All rights reserved.