About 60 firefighters raced to the prestigious school at 29 Fort Greene Place about 10:45 a.m. in response to a call of a fire in the walls of a bathroom, the spokesman said.
Students said the fire spewed smoke into the hallway.
"The smoke had a really strong scent," said Daniel Mishiyeb, 17.
The school was evacuated as a precaution and no injuries were reported, the spokesman said.
The blaze was brought under control about 11:30 a.m. and students were allowed to return to the building, the spokesman said.