Teachers have walked off the job and swarmed South Australia’s Education Department headquarters in a fight for better pay and conditions.

A gathering of thousands brought Adelaide traffic to a standstill as public school and pre-school teachers made their concerns clear.

They were driven to action by stalled negotiations over a new deal for better work conditions.

Almost 200 schools were forced to close their doors for the morning of the half-day strike.

The SA Government claims teachers want more pay for less time in the classroom.

The Education Union's Howard Spreadbury said teachers do want more money, but it is not their primary concern.

“They need to take us seriously and start listening to what we're putting to them in relation to our members' conditions and the learning environments for all of our students,” he said.

“We're pleased with the massive turnout of our members and community supporters sending a clear and definite message to the Marshall Government that they need to take us seriously and start listening in relation to our members conditions and the learning environments for all of our students.”

The union says it will continue to use every tool it can to make the government listen.