Some parents say they won't let their children cross the picket line.
"Instead of going into a classroom what we're going to do is stand with our teachers shoulder to shoulder on sidewalk," said parent Di Molina.
The district has planned for substitute teachers and security at the 56 campuses.
"It won't be a normal school day in senser they'll be with a teacher and rotating periods..may lok a llitle differetntly," said Julie Hatchel, a Capistrano Unified School District spokesperson.
The strike comes after nearly a year of unsuccessful negotiations. Last month the school district imposed a 10-percent cut to benefits and pay.
This week, the Capistrano Unified Education Association (CUEA), the teachers union, offered to return to negotiations and accept the cut if it's temporary, ending in June 2010.
The union gave the district until Tuesday night to accept or face a strike. The district replied, saying it is willing to meet with the union but could not agree to the union's terms up front because it would constitute an unfair labor practice.
"Any preconditions would be set aside so we can actually talk and have an authentic discussion about issues at hand," said Hatchel.
"Our interpretation from the letter they gave us last night is they're not interested at all in making the cuts temporary," said CUEA President Vicki Soderberg.
The district says school campuses will be open. If parents choose to keep their children home, they will be counted as absent.