The State School Teachers' Union of WA (SSTUWA) advised its members to stop work for half a day on Tuesday to protest against the state government's pay rise offer for primary and high school teachers.
SSTUWA president Matt Jarman said teachers and school leaders were overworked and underpaid and leaving the public education system in droves.
"If we want to attract and retain the best teachers in WA, they need to be paid adequately and have manageable workloads," he said.
Mr Jarman said teachers were battling with increasing class sizes, growing violent behaviour in schools and managing the needs of children with neurodivergence.
"The SSTUWA has continued to bargain in good faith with the Department of Education to get an appropriate offer, and we do not take this stop-work action lightly," he said.
"We do understand there may be some impact on parents, but we hope they understand it's a necessary step to ensure our members' concerns for their children's education are heard."
The union directed members to take protected industrial action after rejecting the government's second offer.
The government has offered an increase of five per cent in the first year, followed by three per cent in each of the following two years.
The union has asked for seven per cent in the first year followed by five per cent and a range of improvements in conditions and workload issues.
Treasurer Rita Saffioti on Monday said the government's offer was fair and there was no need for the strike.
She said the government was willing to continue negotiating.
"We've got a very, very good offer on the table ... we ask them to positively engage with us," Ms Saffioti said.
"We understand that everyone always wants more, but from a government perspective, we're going to balance the ability to fairly give wage rises but also manage the entire budget."
