Purpose: The main aim of this work is to present a method for manufacturing nanocomposite consisting of single and double-walled carbon nanotubes and rhenium nanoparticles. A decoration process was started with functionalization of CNTs, then placed CNTs in a medium containing rhenium precursors, inserted it in quartz vessel and finally heating wet material in the atmosphere of H2 and in the shield of inert gas Ar. Design/methodology/approach: The microscope examinations of single- and double walled carbon nanotubes decorated with Re were carried out with the TEM and STEM mode using an HAADF detector. An energy dispersive spectroscope (EDS) was employed to determine chemical composition of the material. Findings: This paper shows the fabrications of SWCNTs/DWCNTs–Re hybrid nanostructures. The researches has found that rhenium nanocrystals are located in the outer walls and in the core of the carbon nanotubes. Research limitations/implications: The development of CNTs decorated with metal nanoparticles has concerned intensive interest in the last decade because of their outstanding sensing properties. CNTs-based gas sensors are attractive because of their small size, low weight, low power consumption, ultra sensitivity (high and prompt response). Originality/value: Rhenium is a heavy metals, possesses very high melting and boiling point, good electrical and thermal properties, and is used in the developing industries such as space, electrical, petrochemicals, chemicals. Searching for new uses of Re, including as a component of nanocomposites composed of CNTs is purposeful and interesting.