The accident took place around 3 a.m. near Hasiyasar village on Jaipur-Ganganagar road in Churu district, some 350 km from here.
"The private bus was carrying over 50 passengers. It lost control and rammed into the truck coming from the opposite direction," said a police officer.
At least 10 passengers died on the spot, while four others succumbed to injuries at various hospitals in the area.
Residents of nearby villages also joined the rescue operation and helped the police in rushing the victims in hospitals at Bikaner, Sikar and Hanumangarh towns, the officer said.