Thirteen-year-old Joshua Troutt says he and three other students were in their classroom at Highland Middle School near Indianapolis.
They were using a school-issued iPad.
Troutt says one of the students pressed a button and the naked photo of his teacher suddenly appeared on the screen.
He says it's the teacher's fault.
"We couldn't do anything not to look at it, if it just popped up when he pressed the button," he said. "It was her fault that she had the photo on there because her iPhone synched to it. She had to have pressed something to make all of her photos sync onto there."
The school district says it has taken preventative action against the teacher.
Many parents say the teacher should be fired.