A Fire and Emergency NZ spokeswoman said crews were called to the Urbanz Accommodation Christchurch hostel on Manchester St, near the intersection with Gloucester St, in central Christchurch about 1am on Thursday.
One person was taken to Christchurch Hospital for smoke inhalation as a result.
The man was reportedly rescued from a room in the hostel and is in a serious condition.
The fire was put out by the inbuilt sprinkler system, authorities said.
The damage to the building does not appear to be severe, Fire and Emergency NZ said.
But the room involved and others in the building may have water damage.
Firefighters have since left the scene. A fire investigator is due to return to the building this morning to determine the circumstances of blaze.
