Students were caught with drugs in 2173 incidents at school last year and the youngest child to be stood down was in year 3.
But the figure is the lowest in three years, according to preliminary data.
Last year, there were 1324 stand-downs and 849 suspensions in New Zealand schools for drug-related behaviour (including substance abuse), according to figures released to the Herald.
The Ministry of Education said the data was still being updated by schools and so could not be compared with other years, but previous figures have quoted there being 2441 drug incidents in 2009 and 2690 in 2010.
A year 3 student - aged between 7 and 8 - was stood down in the Manawatu-Wanganui region. The youngest to be suspended were two year 5 students - aged between 9 and 10 - in Gisborne and Wellington.
Gisborne had the highest number of incidents per capita where students were caught with drugs, with a total of 77 suspensions and stand-downs from a roll of 9353.
A stand-down is the removal of a learner for a period of up to five days, with the decision made by the principal. A suspension is the formal removal of a student until the school's board of trustees makes a decision about when they can return.
Secondary Schools Principals' Association president Patrick Walsh said students bringing drugs to school was a major concern. It was one of the main reasons for disciplinary action against students.
"There wouldn't be a school in the country that wouldn't from time to time have to deal with students who either bring drugs to school to deal in them or to use them in school," Mr Walsh told the Herald.
Included in last year's student drug busts was the 14-year-old girl at Hamilton's Fairfield College who in November gave pink pills to seven of her friends after stealing the drugs from her mother's handbag.
The students reacted badly to the banned drug BZP and, with the aid of parents, the school nurse and deputy principal, had to be admitted to the emergency department at Waikato Hospital.
The girl told her friends the drugs were Ecstasy. She was stood down for the rest of the school year and has not returned to the school.
Her mother was sentenced yesterday to 80 hours' community work for possession of class C drugs.
Mr Walsh, who is the principal of John Paul College in Rotorua, said schools were noticing it was mostly older students who were caught with pills because they were more into the clubbing scene.
The vast majority of the drug busts involved cannabis and schools often noticed a spike around "harvesting season" in April and May, Mr Walsh said.
"A point other principals have made to me is that with the increasing cost of cigarettes in dairies, that the preferred drug in those circumstances, because it's sometimes cheaper, is in fact marijuana."
Students usually got the drugs from their parents or another family member, he said.
"One of my concerns is that schools are increasingly becoming seen as the silver bullet to solve all societal ills ... but the reality is that these things are not caused by schools. We deal with the effects of it," Mr Walsh said.
New Zealanders are among the highest users of illegal drugs in the world, and top the list for cannabis use, according to the United Nations 2012 Drug Report released last week.
Statistics for Oceania - mainly from Australia and New Zealand - showed a far higher prevalence of all drug use, other than heroin, than the rest of the world.
Cannabis use in Oceania was the highest in the world with between 9.1 and 14.6 per cent of people reportedly using the drug, compared with 2.8 to 4.5 per cent globally.