The van, carrying 17 people, collided head-on into an incoming container truck at 2:30 a.m. in Quang Nam province, said provincial Mayor Dinh Van Thu.
Ten people died at the scene and three others when they were rushed to a hospital, Thu said.
According to local news website VNExpress, the four passengers who survived the crash were in critical condition, including two 6-year-old children.
The entourage, from the groom’s family, was on a 450-kilometer (280-mile) drive to the bride’s family in Binh Dinh city, where the wedding was scheduled to take place later Monday.
Photos of the accident posted on VNExpress show that both vehicle fronts were smashed and the van windshield was shattered.
Police have launched an investigation into the incident, Thu said.
Road traffic accidents claim about 14,000 lives every year in Vietnam, according to the World Health Organization.