Italian diplomatic authorities are Italian Embassies, Consulates, or Cultural Institutes, etc. in countries other than Italy.
With reference to foreign study qualifications, the competent diplomatic authority is normally the Italian Embassy/Consulate closes to the place where the awarding institution is located; this is the case when the qualification concerned belongs to the education system of the same country.
Instead, when the awarding institution is part of the education system of another country, the competent diplomatic authority is the Italian Embassy/Consulate General in the country of the education system of reference.

In order to find your Embassy/Consulate go to the website: http://www.esteri.it/MAE/EN/Ministero/LaReteDiplomatica/Ambasciate/default.htm