Smollett was attacked by two people who were "yelling out racial and homophobic slurs" and "poured an unknown chemical substance on the victim," police said.
One of Smollett's alleged attackers also put a rope around his neck, according to police. Both fled the scene.
Smollett took himself to Northwestern Hospital and "is in good condition," authorities said.
As of Tuesday evening, a Chicago police spokesperson told CNN that investigators canvassed the neighborhood where the reported attack occurred and have found no still images or video from security cameras of the incident.
The only image of Smollett police obtained from security cameras was inside a Subway sandwich shop near the location of the reported crime. The actor was seen standing alone.
A dozen police detectives, with the assistance of the FBI, are working the case, according to police spokesperson Anthony Guglielmi.
CNN's Don Lemon spoke to Smollett and a mutual friend who was at the hospital with the actor. Smollett confirmed the incident took place.
He was shaken and angry that an attack like this could happen. Smollett told CNN he fought back at the attackers.
"Given the severity of the allegations, we are taking this investigation very seriously and treating it as a possible hate crime," the police statement said.
Investigators are testing the chemical Smollett said he was doused with and have yet to confirm the nature of the substance.
Smollett has starred on Fox's "Empire" since 2015. He plays Jamal, a successful singer in the musical Lyon family. Like his character, Smollett identifies as gay.
"We are deeply saddened and outraged to learn that a member of our 'Empire' family, Jussie Smollett, was viciously attacked last night," a representative of 20th Century Fox Television and Fox Entertainment said in a statement to CNN. "We send our love to Jussie, who is resilient and strong, and we will work with law enforcement to bring these perpetrators to justice. The entire studio, network and production stands united in the face of any despicable act of violence and hate -- and especially against one of our own."
A representative for GLAAD told CNN the organization has reached out Smollett to offer assistance and support.
"Jussie is a true champion for LGBTQ people and is beloved by the community and allies around the world," a GLAAD spokesperson said in a statement.
Anyone with information is asked to call Area Central Detectives at 312-747-8382.
CNN's Don Lemon and Ryan Young contributed to this report.
