Part of Glasgow Airport was evacuated after a suspect package was found in the search area of a terminal.
A security officer thought a bag was suspicious and police were called in at about 2000 GMT on Wednesday.
The bag and its contents were deemed to be safe about four hours later, a spokesman for Glasgow Airport said.
Some 50 passengers were evacuated while the bag was screened. The spokesman apologised for the inconvenience but said safety was a priority.
As well as the search area, the adjacent road at the front of the terminal was also cleared during the scare.
The bag was reunited with its owner after it had been examined.
The last two flights due to leave the airport, Easyjet's 2055 to Gatwick and British Midland's 2125 service to Heathrow, were both delayed.
There were also some delays in getting passengers off aircraft because of the partial closure of the terminal, the airport spokesman said.
"Following the discovery of a suspicious bag within a security search, the local area was temporarily evacuated until such time as Strathclyde Police could declare the item safe.
"Working in partnership with Strathclyde Police the terminal was returned to normal operations as quickly as possible."
Assistant Chief Constable Ruaraidh Nicolson said: "While this incident has turned out to be a false alarm, there is no doubt that the initial action taken by the staff at the airport was absolutely correct.
"I'm sure that the relatively small number of people who had their travel plans disrupted will understand the necessity of carrying out such operations."