It is of course easiest and cheapest to leave your luggage in your hotel on the day of your departure. If the hotel does not provide this service or if your accommodation is too far from the center you can store your suitcases in Roma Termini’s luggage department.
The luggage department in Roma Termini can be found on level -1, between platform 24 and Via Giolitti. In case you can not find it, the Italian word for “luggage storage” is deposito bagagli.
There are no lockers in Roma Termini. You hand in your luggage and get a numbered slip with which you can pick up your backpacks or suitcases again.
For the first 5 hours you leave your luggage there you pay a fixed rate of 5 Euros per item. For the next 7 hours the cost is 0,70 Euro per hour and after that it becomes 0,30 Euro per hour.
Termini’s luggage department is opened from 6am until 11pm.
There is one, big, drawback: During the high season the queues can be very long, both when you check in your luggage and when you collect it, so if you want to catch your plane or train you had better make sure to be there early.