Arrests for drug driving in the run up to Christmas went up 28 per cent across Hampshire and the Thames Valley.
Drink driving arrests for the same period fell by 5 per cent compared to the previous year.
The region's Road Policing Unit released the figures following their Christmas campaign, known as Operation Holly.
The Thames Valley and Hampshire Roads Policing Unit say that the increase partly because officers can now carry out drugs tests at the road side.
But they are still warning drivers to think twice before driving under the influence of drink or drugs.
Operation Holly is run every year in December, aimed at targeting drivers under the influence of drugs or alcohol.
Police arrested 666 drivers who tested positive for drug or drink in their system during the campaign.
They carried out more than 4,200 breath tests.
They also tested 284 drivers for drugs, with more than half of those tested coming back positive.