On December 6, 1943, Vizzini participated at the first clandestine regional convention of the Sicilian separatists movement of the Sicilian Independence Movement (Movimento Indipendentista Siciliano - MIS) in Catania. Other prominent Mafia bosses like Giuseppe Genco Russo, Gaetano Filippone, Michele Navarra and Francesco Paolo Bontade did not hide their sympathies for the separatists either.
On December 6, 1943, Vizzini attended the inaugural clandestine regional meeting of the Sicilian independence movement (Movimento Indipendentista Siciliano - MIS) in Catania. Other Mafia leaders such as Giuseppe Genco Russo, Gaetano Filippone, Michele Navarra, and Francesco Paolo Bontade showed their support for the separatists.