A PROCESS FOR MAKING NITRILES FROM ALKYL SUBSTITUTED AROMATIC HYDROCARBONS BY CONTACTING VAPORS OF SAID ALKYL AROMATIC HYDROCARBONS AND VAPORIZED AMMONIUM POLYSULFIDE AT A TEMPERATURE OF ABOUT 300* TO ABOUT 500* C., AT ESSENTIALLY ATMOSPHERIC PRESSURE, AND IN THE PRESENCE OF A CATALYST COMPRISING AHIGHER OXIDE OF ELEMENTS OF GROUPSV-B, VI-B, THE LANTHANIDE GROUP, AND THE ACTINIDE GROUP.