Firefighters were called to a block of flats in Ardencraig Drive in the Castlemilk area of Glasgow at about 10:20pm on Thursday.
Six people were rescued from the building while another woman escaped through a window. All suffered from smoke inhalation.
Group manager Brian Winter said: "The firefighters led six people - three children, a woman and two men - to safety after quickly extinguishing the flames using a high pressure water jet. A second woman had already left her flat via a window.
"All seven casualties were cared for by firefighters and paramedics at the scene before being taken by ambulance to the Victoria Infirmary. Specialist fire investigation officers attended and are liaising with the police."
The fire began in the close of the building, and the fire service issued a warning for residents to check their property is protected by smoke alarms.
Mr Winter said: "Any fire within a communal close is extremely dangerous. Even small fires produce large amounts of toxic smoke, which will very quickly spread far beyond the area affected by the flames.
"It is important that communal closes and stairwells are kept free of any materials that could be involved in a fire or impede people attempting to leave the building. Working smoke alarms save lives."