Violence, abuse and dangerous behaviour have sparked 390 stand-downs, suspensions and permanent student dismissals from Hawke's Bay schools this year.
Education Ministry figures released under the Official Information Act show nearly half were due to physical assaults on staff and students.
Over 180 violent incidents resulted in disciplinary cases in the year to October 16, with nine students permanently dismissed from school.
Hawke's Bay figures relate to schools in Wairoa, Napier, Hastings and the Central Hawke's Bay.
Nelson Park School principal Nevan Bridge said developing a positive school culture was the best way to deal with violence.
Students had to think about what they have done, why it was wrong, and how they could have dealt with the situation differently, Mr Bridge said. As a result, "instances in our playground" had significantly dropped in the past nine years.
Last November, Flaxmere College student Adriana Kemp was left with spinal injuries after being brutally attacked by two classmates.
The 14-year-old had screws inserted into her skull to keep her spine straight after the incident, which was captured on another student's cellphone.
However, the number of disciplinary cases for violent and dangerous behaviour across Hawke's Bay schools has fallen in recent years - down 34 per cent in the last year alone.
Mr Bridge said only one child had been suspended at the Napier school in nine years.
"We work really hard at making it work for the child. We really reinforce the message of friendliness, courtesy and co-operation."
Nationally, violent and harmful behaviour offences accounted for more than half of all primary and secondary student stand-downs, suspensions and permanent dismissals from primary and secondary schools this year.
Of the 17,558 disciplinary cases, nearly 9000 were for violence, abuse, dangerous behaviour or weapons offences.
New Zealand Principals' Federation president Paul Drummond said removing pupils from school was a last resort. Many schools had introduced programmes aimed at promoting positive learning cultures and discouraging anti-social behaviour. Student disciplinary cases for violence and dangerous behaviour have dropped significantly in recent years, down 30 per cent since 2009.
But the decline may not necessarily correlate to less violence in schools, Mr Drummond cautioned.
"Schools have put a lot of resources into managing serious behaviour and whether or not that's reflective of a decrease in anti-social behaviour outside the school gate - I just don't know.
"There are still obviously instances of serious misconduct that are challenging to manage."
Many violence offences involved male students in their intermediate and early high school years. "Just by their normal maturation they are starting to challenge and it's also a time when some children are starting to be disengaged from school."
Sadly, violence among primary school students was not uncommon either, Mr Drummond said.
Post Primary Teachers' Association president Robin Duff said some schools were reluctant to impose disciplinary action against students or report them to the ministry. They feared being judged by parents on the number of violent incidents that occurred.
"There is some pressure on principals and boards to keep it [violent and dangerous incident reporting] in-house."
Figures include physical and verbal assaults on staff and students, weapons offences and "other" types of harmful or dangerous behaviour.
Stand-down: Removal of a student for up to five days. Decision is made by the principal.
Suspension: Formal removal of a student from school until the board of trustees decides the outcome at a meeting. The board can extend or lift the suspension, or terminate the student's enrolment at the school.
Exclusion: Permanent termination of a student, aged 15 and under, from school.
Expulsion: Permanent termination of a student, aged 16 and over, from school.
Source: Education Ministry