The teachers are protesting a two-percent pay reduction, cuts to health care benefits and two required furlough days that were put in place in November due to the state's ongoing budget crisis.
"This is being forced upon us by the district," said Danette Brown, president of the La Habra Education Association.
The big sticking point is that the district wants to make the cuts permanent.
Brown said with the cuts, the average teacher would lose $14,000.
"Because the district's cuts are permanent - unlike those in any other district in Orange County - the career impact for La Habra teachers is staggering," Brown said.
Susan Belenardo, superintendent of the La Habra School District, said the school board is willing to rescind the cuts if finances allow, but say they can't guarantee it.
"We don't know what tomorrow is going to bring, and the board's primary responsibility, in addition to educating children, is maintaining the fiscal solvency of the district," Belenardo said.
Extra security was on hand as students arrived on campus. Teachers will be picketing at each of the district's nine schools, and there are 225 teachers involved. District officials say substitutes and administrators will teach classes during the strike.
Parent Brighid Pulskamp said she was pulling her daughter from school earlier to support the teachers.
"I just don't think it's fair to the teachers, and it affects my kids' education," she said.
No new talks are scheduled, and both sides say that they are prepared to go on as long as it takes.