It's an eye-popping report that could partly explain why certain students aren't doing well in school.
The Commission on Teacher Credentialing found nearly 6-1/2 percent of all California teachers were assigned to a class they were not qualified to teach.
The civil rights law firm Public Advocates had to sue the state to force it to gather the numbers.
"The report found that over 22,000 teachers were mis-assigned, meaning they weren't credentialed to teach their subject or trained to teach English learners," said Liz Guillen, Public Advocates.
The majority of the mis-assignments were in classrooms where English was a second language, thereby affecting Latino students the most.
There were 1.6 million "English Language Learner" students in California last year.
"English learners are not getting the teachers they need to succeed in California schools or our state. That's a big problem," said Guillen.
The problem is evident in state standardized tests. The California High School Exit Examination, for example, shows that of all California seniors who took it in March, more than 93 percent passed it. However, for just English learners, only 77 percent passed.
"It's upsetting," said Gretel Quintero, an English learner student.
Quintero began school in California before she could speak English. She feels many of her teachers didn't have the skills to help her.
"They were nice and everything. But if they were more prepared, maybe my English would be better. My education would be better too," said Quintero. "I believe in equal opportunity, and that's not given to us, you know?"
State officials say they welcomed the report. They say it would serve as a good backdrop as the state moves forward to fill every classroom with qualified teachers.