About 200 students walked out of their classes at Lynwood High School for the third consecutive day to protest a decision to start year-round programs July 1.
The students walked out Monday, Tuesday and Wednesday. Parents and supporters also held a protest rally Monday.
Parents said they believe the year-round system will interfere with family vacations and create additional child-care costs.
Officials of the Lynwood Unified School District said year-round schedules are necessary because the district of nearly 16,000 is running out of space on its 12 campuses.