The unwary visitor received the bumper bar bill for a drink sipped near Rome's most famous street, Via Veneto, where beers usually cost as much as 10 euros, Rome mayor's office said.
The tourist, who was traveling alone, was invited to the bar by a tout who served him a beer and then said it would cost him 990 euros. He bartered it down to 490 euros, but the bar owner ended up taking 990 euros off his credit card anyway.
"When the bill arrived I thought it was safer to pay it. I was scared something could happen to me if I didn't," the man, whose name was withdrawn, told Rome mayor's office that is investigating the crime.
The tourist, who is from Hong Kong but lives in Germany and has a British passport, tried to report the fraud to the police but said he could not make himself understood because no one spoke English.