A process for the preparation of a metal-doped pentasil-type zeolite comprising the steps of:

a) preparing an aqueous precursor mixture comprising a silicon source and an aluminum source, at least one of these sources being doped with a rare earth metal or a transition metal of Groups Vb-VIIIb, Ib, or IIb of the Periodic System, and

b) thermally treating the precursor mixture to form a metal-doped pentasil-type zeolite.

With this process, metal-doped pentasil-type zeolites can be prepared while the risk of precipitation of the dopant as a separate phase is minimized.