A Northland high school has credited a drastic drop in violent behaviour and improved student mental wellbeing to a youth worker's lunchtime programme.

Dargaville High's sole youth worker Mel Russell launched a lunchtime programme this year aimed at keeping students out of trouble - and it has been such a success it has captured the attention of other schools throughout the country.

The programme - which runs three times a week - started with just a few students, but has become so popular about 50 now attend each session.

Ms Russell said many students at the Decile 3 school, which she also attended when she was growing up, struggled with low self-esteem, anxiety and depression.

"When I went to this school, there were only three of us Māoris in Year 11. I can see their struggle, I can feel their pain. I can understand what they're going through. I have had no qualifications whatsoever, other than to bring to them my life's experiences," she said.

She found many were smoking and fighting during lunch breaks, causing major issues for staff. Her solution, the lunchtime programme, aimed to solve that.

"They know that they can come to me or that I can talk to them. I know when things aren't right. It's having someone who isn't a teacher or counsellor that they can trust.

"I help them make sense of the nonsense ... they think there is no hope ... all they want is to be heard."

Dargaville High principal Mike Houghton said the programme had been a huge success, and was one of the main reasons there had been no suspensions so far this year - the first time in 25 years.

"Mel Russell plays a vital part in our school and she has absolute aroha for students and wants the best for them," Mr Houghton said.

In previous years, about a dozen students have been suspended each year, mainly for violence-related incidents.

The change has rippled out through the community, with Northland police fundraising $120,000 to provide gym gear and even starting their own weekly programme at the school mentoring youth - many whose families are involved in gangs - in an early-morning gym session.

Ms Russell is part of a network of youth workers with 24/7 - an organisation which links churches and schools - providing 165 staff to 75 schools throughout the country.

24/7 youthwork national network coordinator Jay Geldard said youth workers like Ms Russell were making big impacts through small steps.

He said youth workers had the ability to build trusted relationships with young people, and their work was crucial for helping students - especially around mental well being.