Part of Dunedin Hospital was evacuated after smoke alarms were triggered in the building.
The Fire Service was called at 11.38am and searched the building for the source of the smoke.
Southern District Health Board chief executive Carole Heatly said the Gastroenterology Unit on the 8th floor of the Ward Block was evacuated.
However it turned out to be a false alarm and most crews have since been stood down.
Ms Heatly said everyone was returning to the building and the reason for the false alarm was being investigated.