A police report says conmen are stealing around £7 million a year from tourists, and there are fears they will step up their activities as thousands of visitors head to Scotland this year.
The scammers work by selling fake airline tickets and holiday packages over the internet, duping the unwary into thinking they have booked with a reputable firm. But when travellers arrive at the airport or their accommodation they find that they have been conned.
The report, from the City of London Police's National Fraud Intelligence Bureau (NFIB), showed that during a 12-month period more than 4500 cases of holiday booking fraud were reported.
The NFIB, travel organisation Abta and the Get Safe Online initiative are all warning of possible fraud ahead of the Ryder Cup, the World Cup in Brazil and the Commonwealth Games.
One couple were left more than £1000 out of pocket after being conned into booking a holiday at Loch Ness at a lodge that did not exist.
The report showed that 30% of holiday fraud victims in 2013 were scammed by the fraudulent advertisement of holiday villas and apartments, with some arriving at their destination to discover they had nowhere to stay.
Airline ticket fraud accounted for around 21% of the total scams.
NFIB director Detective Superintendent Peter O'Doherty said: "The internet has changed the way we look for and book our holidays. Unfortunately it is also enabling fraudsters to prey upon those looking for that perfect break."
Get Safe Online chief executive Tony Neate said it was vital for holidaymakers to do their research before booking.