And the rise in the number of positives tests comes despite fewer roadside tests being carried out.
"
During this campaign we have had several drivers who have been three and four times over the legal limit
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Sergeant Nigel Whitehouse
Out of 5,064 tests administered in Wales over a two-week period in December last year, 265 motorists were over the drink-drive limit, a rise of 1.5% on 2001.
However, fewer drivers involved in collisions provided positive breath tests.
Police stopped 11 people found to be driving whilst unfit through drugs - 5.2% of those committing offences.
Four of the arrests were made by North Wales Police which introduced a scheme last year which trains officers how to detect and prosecute drug-driving offences.
Of the four Welsh police forces, only North Wales Police recorded a drop in the number those caught drink-driving.
Across north Wales, 58 people were caught driving while over the legal limit of alcohol compared to 77 over the same period last year.
Tested
Dyfed-Powys Police breathalysed 1,496 people compared to 1,681 last year and the number of positive tests was 55, compared to 44 last year.
A total of 160 people were breathalysed after a collision, with one in 10 proving over the limit.
Last year, 159 people were tested in similar circumstances, with 10 giving positive results.
In the South Wales Police force area, of 217 people tested after a collision, six were positive. In total, 1,097 people were tested.
Sergeant Nigel Whitehouse, South Wales Police community Traffic Safety Officer, said: "During this campaign we have had several drivers who have been three and four times over the legal limit.
"This behaviour is totally unacceptable."
Gwent Police Assistant Chief Constable, Bill Horne, added: "It is sad to see that 265 drivers were so unconcerned with their own safety and that of others, that they were willing to indulge in the criminal use of their vehicles."