Fire crews were called to the Fiddler's Elbow in Picardy Place, near Princes Street, in Edinburgh at 2.30am yesterday when a false ceiling collapsed inside the city hotel.
A full emergency operation was launched as all services scrambled to the scene and the street was cordoned off.
The incident set off fire alarms which alerted hotel guests and clubbers at the GHQ venue, located in the basement of the building.
There were seven fire crews at the scene including two special urban search and rescue teams who quickly established there was nobody trapped inside.
Ambulance crews were also in attendance, including a special operations response team, but there were no casualties.
A spokeswoman for Lothian and Borders Fire and Rescue Service said: "A first floor ceiling had collapsed on to the ground floor.
"Five pumps were in attendance and a further two special urban search and rescue teams were deployed into the collapsed area where it was quickly established that everyone was accounted for.
"A building control officer from the council was there and ScottishPower and Scottish Gas were requested by the fire service.
"The building was left safe and no casualties were recorded."
A police spokesman said: "The collapse triggered the fire alarm and alerted the people inside, they were outside before the emergency services arrived."
The Fiddlers Elbow is a popular bar that bills itself as a 'shabby chic' hotel located in the heart of Edinburgh and would have been packed at the time of the incident.