Armed raiders got away with more than €100,000 when they held up a trader as he returned to his home from Slane early today.
The victim had run a food and refreshments stall at the show in the grounds of Slane Castle, Co Meath, which was headlined by the Stereophonics.
The man was returning to his home in Dublin - 30 miles from the open-air concert venue - when the gun gang struck.
In a well-planned attack, they waited in a garden in Finglas, and when the man returned this morning held him up at gunpoint and forced him to hand over the cash.
At least four men were involved in the robbery, two of them with shotguns and two with handguns.
The raiders escaped in a silver-coloured car, gardai said.
Their victim was not hurt.
Meanwhile, gardaí made 90 drug seizures at yesterday’s day-long event, and there were 18 arrests.
The annual show - the 21st since the first concert at Slane - was attended by a crowd of 60,000.
On the bill with the Stereophonics were the Charlatans, Nickelback, Counting Crows, Ocean Colour Scene, Doves and Irish band The Revs.
But attendance was down on last year’s two-day performance by U2, who attracted a total of 200,000 to the natural amphitheatre beside historic Slane Castle, home of Lord Henry Mountcharles.