There was a 12% drop in the number of people testing positive during police drink-drive tests this Christmas.
Welsh officers breath-tested 3,000 more drivers this Christmas
Of 14,194 breath tests conducted across Wales in a month-long campaign, 564 drivers - 5.2% - failed.
Welsh forces, issuing the results of the 2006 crackdown, said the fall in offenders was "encouraging".
But they were still concerned at what they called the "irresponsible actions" of the minority who continue to get behind the wheel over the legal limit.
Police adopted a zero-tolerance approach to drink-driving this Christmas, launching the campaign in conjunction with the Welsh Assembly Government on the opening day of the Wales Rally GB.
Tests were carried out during routine roadside checks, or following road traffic collisions.
DRINK-DRIVE CAMPAIGN 2006
South Wales: 3961 tests, 219 positive (5.5%)
North Wales: 4404 tests, 133 positive (3.02%)
Dyfed-Powys: 3132 tests, 96 positive (3.07%)
Gwent: 2697 tests, 136 positive (5.04%)
Source: Welsh police forces, 1 Dec 2006-2 Jan 2007
Information from the public also allowed officers to carry out intelligence-led operations thoughout the campaign, targeting people who drove while under the influence.
North Wales Police carried out the most tests in the month-long period from 1 December 2006 to 2 January 2007. Of 4404 drivers tested, 133 gave positive readings.
In South Wales, 3,961 drivers were tested, and 219 were positive.
In Gwent the figure was 136 from 2,697 tests, and in the Dyfed-Powys force area 96 tested positive out of 3132.
There were also 19 arrests across Wales for driving under the influence of drugs, four in north Wales, six in south Wales, and nine in Gwent.
Sgt Graham Thomas, road safety officer at South Wales Police, the lead force behind the All-Wales drink-drive campaign, welcomed the drop in positive tests.
"Thankfully there is an ever-increasing number of drink-drivers who have realised just how anti-social and dangerous drinking and driving is," he said.
"However, having said that, these statistics are still too high, and there can be no room for complacency."
He added: "It is unacceptable that over 300 drivers have chosen to continue to ignore the message, acting without consideration for their own safety and that of others.
"Drink-driving will not be tolerated and we will continue to work together to make our roads safer by taking those intent on putting themselves and others at risk off our roads."