The accident took place late Friday night near Mataur village, around 75 km from Delhi.
The police said that seven people died on the spot while one person succumbed to injuries at the Post Graduate Institute of Medical Sciences (PGIMS) in Rohtak.
The victims were travelling in a Mahindra Xylo multi-utility vehicle when the truck collided with it. Police said that both vehicles seemed to be travelling at high speed.
The truck driver fled from the spot.
The impact of the accident was such that the Xylo, which was badly damaged, fell into fields along the highway.
The victims were travelling from Bahadurgarh town near Rohtak towards Dadri town.