A Chicago Fire Department spokesman said the fire started on the second floor of a large rehabbed 3-flat at 858 West Diversey.
Flames quickly spread to the third floor.
The home is located on the border of Lakeview and Lincoln Park neighborhoods.
Firefighters reported an elderly man and woman managed to get out safely.
They were taken to Weiss and Illinois Masonic hospitals and treated for smoke inhalation.
Both were in admitted in stable condition.
No other injuries were reported.
The cause of the fire is under investigation.