A single crash set off a series of events causing four other crashes on the Bruce Highway at Tanawha last night.
Police say just before 8pm near Ilkley Rd, a car travelling northbound left the road and collided with a barrier.
The driver, a 37-year-old Graceville man, then left this car and ran across the Highway into southbound traffic.
They say a car swerved to avoid colliding with the man and it rolled multiple times.
He was struck by another vehicle a short time later.
He received head and chest injuries and was taken to the Sunshine Coast University Hospital (SCUH) in a serious condition.
Meanwhile, a B-double truck travelling northbound at the time, swerved to avoid the initial crash scene, striking a vehicle in the left hand lane, causing it to roll.
In total, ten vehicles were involved in five separate traffic crashes, with six people transported to hospital.
Three women in their 20s with various injuries were taken to SCUH in stable conditions while a boy and a man in his 60s were taken to Nambour Hospital in stable conditions with head injuries.
Witness or anyone with relevant dashcam footage or CCTV is urged to contact police.
Investigations are continuing.