Schools across the country are closed as educators demand payment of contributions to their salaries, such as meals and transportation fees, plus the passing of an education bill.
Many also oppose redundancies in the teaching sector.
President of the Union of Education Workers of Serbia, Slobodan Brajkovic, addressing the crowd in Belgrade, said that they had gathered "to say that the government can no longer play with them.”
He said that they had negotiated repeatedly with Prime Minister Aleksandar Vucic, Finance Minister Dusan Vujovic and Minister of Education Srdan Verbic but that they had promised to "repair" the financial status of teachers.
After the protest held at Nikola Pasic Square in Belgrade, teachers began a march on the Serbian government building.