Carbon nanotubes (CNTs) are known for a wide range of applications due to their various properties. Because these unique properties of the carbon nanotubes strongly depend on the structure, the primary aim is high efficiency and controlling the nanotube diameter during the production. In this study, single-walled carbon nanotubes (SWCNTs) were synthesized by chemical vapor deposition of acetylene (C2H2) on the Co-Mo/MgO catalyst. The effects of different catalyst preparation methods, Co/Mo, and support material ratios on the SWCNT growth efficiency were investigated by thermogravimetric analysis. Raman spectroscopy, scanning electron microscopy, and an x-ray diffractometer were also used for the structural and morphological characterization of the SWCNTs. As a result of the experimental studies, the optimum Co:Mo and metal/support ratio was determined as 1:3.5 and 15%, respectively. Considerable CNT growth efficiency (73%) has been achieved with the Co:Mo=1:3.5/15% MgO catalyst prepared by the solgel method.