A process for the disproportionation of cumene is disclosed which comprises the step of contacting a feed containing cumene, under disproportionation conditions, with a catalyst comprising a molecular sieve, preferably TEA-mordenite. The contacting step disproportionates at least part of the cumene in the feed to provide a disproportionation effluent containing benzene and a mixture of diisopropylbenzene isomers. The effluent is then recovered and contains, prior to any separation step, less 1% of ortho-diisopropylbenzene by weight of the total diisopropylbenzene content of said effluent, less than 1 wt % of n-propylbenzene, less than 5 wt % of triisopropylbenzenes and less than 5 wt % of disproportionation products other than benzene and diisopropylbenzenes.