The accident took place near Balesar village in Jodhpur district, some 450 km from state capital Jaipur.
Among the dead were 2 women and 2 children.
"All the victims were residents of Gujarat. They were on their way to visit Ramdewara, a famous religious destination near Jaisalmer district. A truck coming from Jaisalmer collided head-on with the jeep," said a police official.
Eleven of the jeep passengers, including two women and two children, died, while at least seven were rushed to a hospital in Jodhpur, some 75 km from the accident spot, where they are undergoing treatment.
"The condition of two of the injured is serious," said the official.