The parents of more than 500 students in Manchester have refused to let their children take the new Smarter Balanced test.
The New Hampshire Union Leader reports the district had received 531 parent refusal notices as of Thursday.
The school board voted earlier this month to send letters home to parents letting them know they could pull their children from the test, which is being given for the first time this spring.
The new statewide assessment is aligned with the Common Core State Standards.
Under state law, parents do not have a right to opt out of testing.
However, Manchester school officials say parents can submit a written refusal and their children will be given other activities while the test is being given.