This paper studies the role of Sn and K on the hydrogen spillover on the Pt/gamma -Al2O3 catalyst. Four catalysts of Pt/gamma -Al2O3, Pt-Sn/gamma -Al2O3, Pt-K/gamma -Al2O3 and Pt-Sn-K/gamma -Al2O3 were prepared, and various techniques were employed to investigate the hydrogen spillover phenomena. Hydrogen temperature-programmed desorption (H-2-TPD) and temperature programmed reduction (TPR) were used to display the hydrogen spillover effect of the catalysts which was found to follow the sequence: Pt-Sn-K/gamma -Al2O3 > Pt-Sn/gamma -Al(2)O(3)approximate to Pt-K/gamma -Al2O3 > Pt/gamma -Al2O3. The aromatization of n-hexane and the catalyst deactivation studies were used to investigate the hydrogen spillover effect. It was found that the results from both studies follow the trend obtained from the results of H-2-TPD and TPR. Furthermore, it was found that there is a synergistic effect; i.e. the catalyst life of the catalyst promoted with both Sn and K is longer than that obtained from the summation of the catalyst life of the catalysts obtained from the promotion with Sn and K only. It was concluded that the promotion of Sn incorporated with K induces more hydrogen spillover on the Pt/gamma -Al2O3 than the promotion of either Sn or K.