Three drunk drivers were arrested leaving Toast Martinborough on Sunday - including one who was more than three times the limit.
Masterton police Senior Sergeant Carolyn Watson said police stopped 398 people at a Ponatahi Rd checkpoint as they left the food and wine festival.
"Although the readings are high, which is disappointing, for that number of people being stopped and only three people found means the message is getting through to the majority."
A Masterton man in his 40s was caught with a breath alcohol limit of 1405mcg at the checkpoint. The limit is 400mcg per litre of breath. Ms Watson said he was "pretty hammered".
A Masterton woman, 24, blew 850mcg and a 20-year-old Martinborough man, who was stopped by a patrol car elsewhere in the township, blew 857mcg.