The primary teachers' union says schools are seeing more extreme behaviour from their youngest children.
Ministry of Education figures show schools stood down five-year-olds 70 times last year, and six-year-olds in 131 instances.
There were six suspensions of five-year-olds and 20 of six-year-olds.
New Zealand Educational Institute (NZEI) president Ian Leckie says schools are feeling the effect of wider societal problems.
But the ministry says the rate of suspension for five- and six-year-olds has not increased in the past five years.
It says the stand-down rate for six-year-olds has decreased but the rate of stand-downs among five-year-olds has risen slightly.