Non-EU Citizens

Depending on the duration of your stay in Italy, you have to apply for a residence permit or not: if you are a non-EU national and plan to come to Italy for a period exceeding three months, you must apply for a residence permit, while if the length of your stay is less of 3 months you are not required to apply for.
If it is your first time in Italy, you have 8 days to apply for a residence permit.  

Non-EU citizens intending to stay in Italy for more than 90 days must apply for a residence permit/permesso di soggiorno. The application for a residence permit must be presented within 8 days of arriving in Italy. For more information, please contact COT that will provide you with the necessary assistance