A man in his 40s was killed when the van he was a passenger in collided with a car, gardai said.
The accident happened on the Rathbeale Road in Swords, Co Dublin, at about 2.30am.
The victim was pronounced dead at the scene and the driver of the van and a second passenger, who are both aged in their 20s, were rushed to Beaumont Hospital.
Their injuries are not thought to be life threatening.
Gardai said the driver of the car was not injured and have appealed for any witnesses to come forward.
Motorists were warned to avoid the area while accident investigators examine the scene. Diversions are in place.