Tuesday, Los Angeles Superior Court Judge James Chalfant issued a restraining order blocking the United Teachers Los Angeles from staging the walkout. The Los Angeles Unified School District had gone to court asking for the restraining order.
Chalfant said teachers who violated his order could be fined $1,000 each and possibly lose their teaching credentials.
Teachers will also hold a rally at the LAUSD's headquarters in downtown Los Angeles after school.
The union also says teachers will take part in an act of "civil disobedience" yet to be announced.
LAUSD Superintendent Ramon Cortines welcomed news that the teachers will not walk off the job Friday.