An Israeli couple flew to Paris but left their three-year-old daughter at the airport.
The pair were late for their flight at Ben-Gurion, Israel's main international air portal, and in their haste failed to realise they had boarded with only four of their five children.
The couple did not recognise their error until they were 40 minutes into their flight, when cabin crew informed them.
A police spokesman said: "It is usual that travellers in a rush forget their luggage, but not a child. This never happens." The girl was put on the next flight to Paris, where she was re-united with her parents.
She was found wandering alone in the duty-free area of the airport.
Police will question the couple when they return from their trip.