Primary teachers and principals will go on strike on August 15.
The teachers union NZEI Te Riu Roa said teachers would stop work for at least three hours next month after the government refused their pay demands.
NZEI lead negotiator Liam Rutherford said the strike from 1.30pm to 4.30pm could be extended to a full day after many members did not think the half-day strike sent a strong enough message.
The decision follows a series of meetings around the country where teachers voted whether they should accept the pay offer or strike.
The Ministry of Education had offered to increase pay, in the majority of cases, by between 2.2 and 2.6 per cent a year for three years.