Over €900,000 has been stolen from people in rental scams over the last two years.
503 cases have been reported to gardaí between February 2019 and May 2021.
Almost half of the incidents occurred in Dublin, while 42% of those scammed were under the age of 25.
There has, however, been a decrease in incidents reported in the last 18 months - with gardaí pointing to COVID-19 restrictions the likely cause of the recent decline.
However, Detective Superintendent Michael Cryan says students are particularly vulnerable at this time of year when looking for college accommodation.
He says people should be on the lookout for warning signs of a scam.
He said: "One is if the rent is a little bit too cheap or much too cheap for the area, or if the landlord is unable to meet you and can only communicate via social media or WhatsApp.
"Another one is where there may be a cloned website - where someone goes looking for accommodation, but unfortunately they're on a cloned website."
He's urging young people to push for direct answers from a potential landlord, and to "disengage immediately" if the responses are vague.
Anyone paying their first rent or deposit should use only trusted money transfer systems, with gardaí recommending a credit card.
They say tenants should never transfer money direct, pay cash, or pay into cryptocurrency wallets.
Det Supt Cryan added: "Be wary if a website is asking you to send money to a random PayPal address, wire it by Western Union, pay in iTunes gift cards or only deals in cryptocurrency.
"The majority of the time, those methods are done to avoid scrutiny and ensure that a transaction can’t be reversed."
The warning comes as the latest Daft report shows there's a 'chronic and worsening' lack of supply in the Irish rental market.
