The accident occurred at 6:00pm near the station of Kritzendorf, about 20 kilometres north-west of Vienna.
Four people sustained moderate injuries and four others light wounds, said Infrastructure Minister Norbert Hofer. One person airlifted to hospital with head injuries but was conscious.
"We believe that the cause was likely human error, not a technical fault. But this will be investigated in the coming days," Hofer said.
Both trains were emptied of people by 7:30pm.