Ion exchange resins, particularly the macroporous variety, are very versatile catalysts, which play a more and more important role in the large scale manufacture of petrochemicals and solvents. Different acid and basic resins have been studied for several reactions in order to improve the catalytic performances and the process engineering with respect to current technology. Strongly basic resins were checked as catalysts for the methanol carbonylation to methyl formate. Strongly acid resins were instead employed in the isobutene dimerization to produce a mixture of ether and branched hydrocarbons, mainly C-8, with high octane number.