The two men were arrested on Tuesday morning while trying to pass themselves off as railway officials for Trenitalia.
The men were caught after they followed a group of Korean tourists onto an early morning train at the station and told them that they needed to pay €20 for bringing their luggage on board with them.
However, Italian police had received a tip-off about the scam and officers from the force were lying in wait in the carriage. After being caught red-handed, the two scammers were arrested, Il Messaggero reported.
Tuesday was a busy morning for the police at Termini, who arrested a further four Romanian pickpockets working in or around the station.
Termini is a notorious hotspot for thieves and scammers, for whom the millions of tourists who pass through the station each year represent easy prey.