The robbery happened around 9:18 p.m. on the 3500 block of North Sheffield Avenue, near Sheffield and Addison, on the city’s North Side, said police.
Investigators said two black males, one of them armed with a 4-inch knife with a black handle, stole the victim’s wallet containing $300.
One suspect is approximately 19-years-old and he was wearing a red hat and a white T-shirt.
The other thief is in his 30s, about 6-feet-tall, 190 pounds with a short Afro.
After the robbery, both offenders ran southbound from 3542 North Sheffield Avenue; which is where authorities said the incident occurred.
Police searched the nearby Addison CTA Red Line station, but as of 9:44 p.m., the suspects remained at large.