A process for preparing an alkylaromatics isomerisation catalyst comprising at least 0.01% wt of platinum on a carrier comprising of from 1 to 9 wt % of ZSM-12 and inorganic binder, which process comprises treating the carrier with an impregnation solution comprising base and an anionic platinum complex which impregnation solution has a pH of from 5.5 to 8; and a process for the isomerisation of alkylaromatics with the help of catalyst thus obtained.