Gallium/H-ZSM-5 zeolite catalysts were tested for the aromatization of long-chain alkenes, namely 1-hexene and 1-octene. Aromatic yields of ca. 70% were obtained, which are similar to those reported in the literature for propene aromatization. The catalysts tested were prepared by impregnation by incipient wetness of gallium nitrate, ion-exchange with gallium nitrate and by physical mixing with beta-gallium oxide crystallites. Hydrogen pretreatment improved the selectivity to aromatic products of gallium/H-ZSM-5 catalysts prepared by physical mixing with beta-gallium oxide, but decreased aromatic selectivity for catalysts prepared by ion-exchange and impregnation.