Members of the NASUWT union are staging the walkout at the East Dunbartonshire Council secondary schools today.
The strike is forcing the closure of Bearsden Academy to most students.
Kirkintilloch High School and Lenzie Academy are also being hit, although they are expected to remain open.
The local authority said it was disappointed strike action was proceeding.
The union issued the strike notice over what it claimed was the council’s “failure to tackle management practices which have an adverse impact on the workload and working conditions of teachers”.
NASUWT general secretary Chris Keates said: “It is disappointing that we have been forced to take action in East Dunbartonshire, but having attempted to engage in constructive discussions to work together on these issues, regrettably the council changed its position and instead of confirming it would work with us on the issues we had raised, would only commit to them informing local discussions.”
The council has “underestimated badly the depth of teachers’ anger and frustration”, she added.
The union said the action was the first in its plans to target councils across Scotland “who fail to act to support teachers to improve their workload and working conditions”.
The council tweeted to inform parents three local schools were being hit by the strike.
It said: “Kirkintilloch HS & Lenzie Academy will be open. Bearsden Academy will be closed to all students except those attending the Language & Comm Unit & those who get transport to college from school.”
Council joint leader councillor Vaughan Moody said: “The threat of industrial action by the NASUWT, targeting only East Dunbartonshire of 32 local authorities in Scotland, is unjustified, unduly personal and a direct attack on the pupils of this area because they are in high performing schools.
“The unsubstantiated claims by the NASUWT that the council has chosen not to engage with them are simply untrue. This council has been instrumental in addressing all issues raised by teachers.”
The other joint leader of East Dunbartonshire Council, councillor Andrew Polson, added: “I would also like to reassure our young people and their families and carers that we are doing everything in our power to minimise the disruption to their schooling through this single union action which is not being supported by the other teaching unions.”