In a 5-2 vote came Tuesday night, the board approved the plan by Frances Gallo, the schools superintendent, to discharge a total of 93 staff members at Central Falls High School.
Gallo made the recommendation last week, stating the move was necessary due to callous disregard by the union.
Central Falls High is one of the lowest-performing schools in Rhode Island. It is in a community where median income is $22,000, census figures show.
Of the 800 students, 65 percent are Hispanic, and for most of them, English is a second language. Half of the students are failing every subject, with 55 percent skilled in reading and 7 percent proficient in math, officials said.
Central Falls High School offers grades 10-12.