Etherification of certain C-6 olefins with alcohols over a commercial ion-exchange resin and some supported sulfated zirconia catalysts was investigated. The commercial resin catalyst Amberlyst 15 shows nonselective to ether production. Silica-supported sulfated zirconia shows a comparable and even higher ether yield than the commercial resin while the catalytic activity is dependent on zirconium precursors, preparation technique, calcination temperature, ratio of SZ on silica, and reaction temperature. Addition of promoters, transition metal oxides, will also influence the catalytic activity while depending on the nature of promoter. Ni and Pt increase the catalytic activity and Fe shows no significant influence on olefin conversion whereas Mn reduces the catalytic activity. However, these promoters reduce the ether selectivity and ether yield. Silica-supported SZ catalysts also exhibit varying activities for etherification of different olefins and alcohols. (C) 2003 Elsevier Science B.V. All rights reserved.