More than 3,000 public educators in Windsor-Essex are taking part in a province-wide work-to-rule campaign.
Teachers in public elementary and high schools in Ontario are not doing administrative work which includes not writing comments on report cards, attending certain meetings and taking part in standardized testing.
At John Campbell Public School, teachers waited in the parking lot and only entered the school 15 minutes before classes began.
Parents outside supported the teacher's campaign.
"I think they have every right to, I think they are underpaid," says parent Maurissa Hastings. "I think they are under appreciated especially considering the education they have."
Parent John Theoret says as long as his child isn't affected, he is in favour.
"As long as the students get their education, that's what I care about."