Fire officials say the three-alarm blaze started on the second-floor of a home on Dahlgren Place in Bay Ridge and spread to the home next door.
Nearly 140 firefighters responded to the fire shortly before 2 a.m.
The Red Cross is helping one family -- a man, his daughter and his son-in-law -- who lived in one of the homes affected by the flames. The homeowner told NBC 4 New York he was watching TV when he saw the fire and hopped a fence to alert his neighbors.
Everyone on the block got out safely, authorities said.
The fire is not considered suspicious, and the cause is under investigation.
-Sheldon Dutes contributed to this story