The fight broke out before noon at the Englewood STEM High School, located at 68th and Normal.
At least four officers were injured while responding to the fight, Chicago police said.
Some students were seen put in handcuffs. Police later confirmed five arrests were made, but there was no further information about possible charges.
"It's always something that happens here," school parent Corey Johnson said,
A stream of Chicago police squad cars led up to the entrance of Englewood STEM High School. Officers worked to bring calm after a large brawl involved at least 100 students on three different floors.
Cell phone video showed the hallway disorder that unfolded after the fight Friday morning.
Parents quickly responded to pick up their children.
"My daughter had called me and told me it was a huge fight at her school, and they had the building on lockdown, and she could not get dismissed until I come and pick her up," school parent Julnita McCoy said.
McCoy told ABC7 her daughter claims another student used pepper spray in the hallway, causing a frenzy.
"She say, 'I have to go to the bathroom and wash my face, because my face has mace all in it.' She was walking to her classroom," McCoy said. "How did a student even come in the building with some mace anyway?"
That's when Corey Johnson said his 15-year-old son got caught up in the fray and was handcuffed while police calmed the crowd.
"He said it was a girl fight, at first, and then it just hit so big that everybody started fighting," Johnson said.
It was a violent situation that, parents told ABC7, speaks to an ongoing problem here at the school.
"At this school, every time you turn around it's fights all the time at this school,"
Police on the scene said there were no weapons involved and some students did sustain minor injuries.
ABC7 has reached out to CPS for more information, but has not heard back.