Almost 7,000 bikes have been reported stolen since January 2020.
New figures released by gardaí show more than 1,000 have been taken since the beginning of this year.
Bike thefts are a particular problem in cities, with more than 4,800 stolen in Dublin since the start of last year, while in Cork more than 300 were stolen.
A video shared by An Garda Síochána as part of its “Lock it or Lose it” campaign shows a bicycle theft on Grafton Street in Dublin city centre.
So far this year every Garda division has had a bike theft reported to officers, except Roscommon-Longford.
Less than half of the stolen bicycles are recovered, with just more than 2,000 given back to their owners since the start of 2020.
Gardaí have offered advice to cyclists to help keep their property safe, including spending up to 20 per cent of the value of the bike on two locks and keeping it in a secure area.
People are also advised to have pictures of their bikes along with the serial numbers, which would help return the bicycle if stolen.
Gardaí have a number of recovered bicycles at Garda stations around the country which have not yet been claimed.
Photos of bicycles which have been recovered but not yet returned to their owners are available by division on garda.ie and on An Garda Síochána’s Divisional Facebook Pages, along with details for owners to claim their bike.