More than 1,350 motorists were tested by Gwent Police as part of this year’s All Wales Summer Anti Drink/Drugs Driving Campaign.
Of those tested, just 32 tested positive in the month-long campaign held in June.
Across Wales, the number was 358 out of a total of 15,485 breath tests.
The South Wales Police area had the highest percentage of positive tests with 144 out of 2,248.
Superintendent Paul Evans, of Gwent Road Policing, said: “Although a minor percentage of the driving public tested positive or refused/failed a breath test, it is very disappointing to see that 32 people are still willing to risk their lives and those of other road users by choosing to drive under the influence of alcohol or drugs – the consequences of which can be extremely serious and far-reaching.
“In the least, those arrested risk being issued with a lengthy driving ban, facing imprisonment and losing their jobs. It’s important to stress though that the work does not stop here. Any amount of alcohol affects your ability to drive, campaigns such as this raise awareness and we will continue to target those breaking the law as part of daily policing.
“Anyone with information about people drinking and driving should call 101 or Crimestoppers anonymously on 0800 555 111.”