Today it's an official language only in Italy, Switzerland, San Marino and Vatican City. Before 1970's there were a lot of Italian speakers in Libya but they were expelled by Ghaddafi regime. Somalia and Eritrea were in the past also Italian colonies but the knowledge of the langiage dropped there now. In Somalia the reason is long time of civil wars which destroyed their educational system. In Eritrea it is because merging it with Ethiopia in the 1950s. It's now an independent country (from 1993) and Italian seems to recovering there. It's taught in the University of Asmara now and in two schools (primary and high school) in Asmara - the capital city of Eritrea. It's also commonly used also in Malta due to its close distance to Italy.

svizzera e san marino

Switzerland and San Marino, as far as I know.

Svizzera, Città del Vaticano e San Marino