According to local media, eight of the eleven occupants of the minibus died at the scene.
A few hours later, a ninth person was confirmed dead in a nearby hospital.
Among the victims was the driver of the minibus.
The commander of Rancagua Police, Manzur Abutom, said the circumstances of the crash were being investigated.
The minibus was carrying agricultural workers and was headed west on the H-66 G route when it crashed into a truck going in the opposite direction.
Presidential Delegate to the O'Higgins Region, Ricardo Guzman considered the accident to be one of the worst this year.