Work-to-rule action could affect the graduating high school students applying to some universities.
The Ontario Public School Boards' Association said this week that the withdrawal from extracurricular activities could last for two more years.
The association said teachers have the ability to impose their job action until Aug. 31, 2014.
As senior students begin to apply for university, some are concerned about what they're missing.
Student government, sports and some theatre have all been put on hold at public boards.
"It's kind of a drag because I like doing sports," said Thomas Leigh, a swimmer in Grade 12 at Kennedy High School in Windsor, Ont.
Ontario public high school students applying to universities within the province aren't affected as much as those applying to universities elsewhere in Canada.
Some schools in other provinces, such as the University of British Columbia, require a personal profile alongside student transcripts.
"We're looking at what students have been involved in, be it sports or volunteer work in the community. In some cases, it's what they learned from part-time jobs," said Andrew Arida, from the admissions department at the University of B.C. "What kind of responsibilities and things they have been doing outside the classroom?"
The university accepted 350 Ontario students in 2012.
"If you're in more extra-curricular activities, it shows more initiative," said Jaden Donaldson, a Grade 12 student at Kennedy High School in Windsor, Ont. "It shows you want to apply yourself more.
At the University of Windsor, students are admitted based strictly on their grades.
"We look for six Grade 12 university courses, their high school diploma and admission is based strictly on grades," said Charlene Yates, the school's acting registrar.
However, the school's assistant dean said extra-curricular activities in high school may play a role in student success at the university level.
"The most common reason for students to voluntarily drop out of any university is because they don't bond with other students," Roy Amore said.
The best way to do that, he said, is through clubs and groups.
Meanwhile, teachers at public elementary schools in Ontario chose one-day strikes to voice their displeasure with Bill 115, which takes away the teachers’ union’s right to strike. High schools chose work to rule, instead.