The 36-year-old man was working as a night watchman at the hotel in Rome when the incident occurred.
It is believed his 30-year old victim, who was from Sweden, was only saved by her screams which alerted her friends.
According to police, a group of Swedish tourists approached a patrol in the street at around 4.30am to report the attack.
Officers returned to the hotel on Via del Corso, a main street in the Italian city, where they reviewed CCTV footage – which captured the suspect wandering out of the hotel room and down the corridor still half naked.
He was later arrested for attempted rape.
Rome’s Mayor Virginia Raggi, who went to visit the tourist after the shocking incident, said: “This is infuriating. These kinds of things are intolerable.
“I have to thank the local police for acting immediately.”
The attack comes less than three months after an Australian woman was beaten and raped next to the colosseum in Rome.
The 49-year-old woman had been walking from a bar through Colle Oppio park when she was attacked, suffering serious injuries in her struggle against the attackers.
She was found lying on the pavement by a passerby, and both her phone and handbag had been stolen.
A homeless man, who she had refused to kiss earlier in the night, has since been arrested and police are hunting a second suspect – who she believes she asked for directions.