Some 176 fewer people were arrested in the first five weeks of this year's Christmas anti-drink driving campaign, compared with last year.
A Garda spokesman said the number of check-points was broadly the same as the previous year. He said it was not possible to say whether fewer people were drink-driving or fewer drink-drivers were being detected.
The annual six-week Garda clampdown on drink driving finished on Sunday night but figures are not yet available for the final week.
Some 1,261 were arrested for drink-driving in the first five weeks of the campaign, compared with 1,337 in the first five weeks of the 2001/2002 campaign.Almost seven out of ten drivers breathalysed were arrested for drink-driving in the recent campaign.
On average, 252 drivers were arrested every week of the latest campaign, compared with 267 drivers during the previous campaign.
Meanwhile, Northern Ireland's drink-drivers have been warned that there will be no hiding place for them throughout the year.
Almost 400 motorists face prosecution in Northern Ireland, after being caught in the Christmas anti-drink-driving campaign.
Assistant Chief Constable Duncan McCausland said the pressure would be kept up throughout the year.
"There seems to be an irresponsible minority who ignore all advice and warnings. That is why the detection of drink-driving is a priority for the police - indeed an all year round priority."
Mr McCausland said 43 people had called Crimestoppers to report drunken drivers, over the Christmas period. This showed the public was not prepared to accept such anti-social behaviour, he said.
One motorist who was detected at 8.40 a.m. in the week before Christmas was five times over the legal limit.
"A lot of the people detected were two or three times over the limit. That is not taking a slight chance," he said.
The youngest drink-driver detected was under 16, while the oldest was 74. The highest level of detections was in the PSNI south region. Mr McCausland said this was a mainly rural area and drivers may have mistakenly believed they could slip safely home down country lanes without encountering police.
