Tourists face charges of drunkeness and threatening Rome police.
Three Australian tourists were arrested at Rome's Trevi Fountain during the night of 14 October, after an altercation with city police, according to Italian news agency ANSA.
Police had asked the tourists to behave more respectfully and not to sit on the edge of the monument when one of the group responded by pouring a liquid, reportedly alcohol, into the waters of the Baroque masterpiece before throwing his glass on the ground and attempting to attack one of the officers.
Local media reported that the tourists were two males, aged 44 and 50, and a 27-year-old woman who fled the scene but was subsequently caught hiding in a bar.
The tourists now face charges of drunkenness as well as insulting and resisting police.
During the summer the city limited access to the over-crowded monument which is increasingly the scene of tourists behaving badly, from naked swims to brawling over selfies.