Maitland's largest music festival returns this weekend, but police are warning Groovin the Moo attendees: get caught with drugs and you won't be allowed in.
Police said new licencing meant people detected with drugs entering or at the event will be told to leave.
In previous years, people caught with drugs were issued with court attendance notices and allowed to enter the festival.
Attendees who are caught with drugs who police believe to be under the influence will be escorted to the on-site medical facility but will not be allowed back in to the event to enjoy the festivities.
There will also be an increased number of drug detection dogs and 140 officers covering the event.
"If you're thinking about bringing illicit substances, there's a very real chance you will get caught," Port Stephens-Hunter commander Superintendent Craig Jackson said.
Superintendent Jackson said there were "inherent dangers" that come with drug use and their approach is about preventing those after several drug related deaths at music festivals in recent months.
"We're trying to make this as safe an event as possible," Port Stephens Hunter commander Superintendent Craig Jackson said.
Pill testing will be available at the Canberra leg of Groovin the Moo, but the NSW Government has refused to allow the initiative in this state.
The Maitland event has sold-out once again, with the likes of Billie Eilish, Hilltop Hoods, DMA's, Fisher and more set to entertain crowds on Saturday.
To avoid congestion around the venue, road closures will be in place on surrounding streets from 8am until midnight.
Organisers have said the most convenient way for festival goers to get to the event will be by bus, and urged those who are getting picked up and dropped off to do so at Maitland Train Station.