People have been warned by Justice Minister Alan Shatter to be vigilant this Christmas despite a drop in most types of crime.
Official figures show there were 17,500 fewer crimes committed in the 12 months to the end of September, but thefts continued to rise.
While burglaries dropped by 10.4% over the year and robberies fell by 5.2%, thieves struck 78,632 times.
There were 20,000 shoplifting offences, 6,100 thefts from a person - including mobile phones - and 44,200 complaints about other incidents including handling stolen goods.
Mr Shatter said gardai have launched a range of operational measures to target the 3.6% rise, including awareness-raising campaigns highlighting smartphone and similar thefts.
"I urge everyone to take great care with regard to where they keep their mobile phones, particularly in the lead-in to Christmas and over the holiday period," he said.
"Don't give an unintended Christmas present of your mobile phone to a thief.
"A great deal can be done by each of us to ensure our phones are safe. For example, never leave your phone unattended in your car.
"Also, when you are not using your phone, ensure that it is safe and secure in your pocket or handbag.
"Simple and straightforward precautions such as these can have a real impact in reducing mobile phone theft offence."
The Central Statistics Office (CSO) showed reductions or no change in 12 out of the 14 categories up to the end of September, and an overall reduction in crime of 7.1% from 248,685 in 2012 to 231,029 in 2013.