In this paper, the results obtained in the methane decomposition reaction promoted by a Ni catalyst supported on MgAl 2 O 4 spinel are presented. The textural properties of the catalyst were investigated by X-ray diffraction (XRD), N 2 adsorption/desorption isotherms (BET and BJH methods), thermogravimetric (TGA) and temperature-programmed reduction (TPR) analysis. The influence of the operating conditions employed on the methane decomposition was studied. According to the results, it was found that a N 2 :CH 4 molar ratio of 7:1 and catalyst reduction temperature of 700°C/1h were the best conditions for methane decomposition. In addition, in the methane decomposition over Ni/MgAl 2 O 4 , multiwall carbon nanotubes were formed.