Students were thrown down the aisle and showered with shattered glass when a truck collided with their school bus on Main Road on Monday.
Ballarat police acting sergeant Daniel York said a truck pulled out of Stanbury Avenue at 3.40pm and crashed into the side of a school bus travelling from Damascus College into Ballarat.
Six students were transported to Ballarat Base Hospital with non-life threatening injuries including cuts and abrasions, a sore back and a wrist injury.
Clare McLennan, 15, said she saw the truck approach from her seat next to window and realised it was not slowing down.
"I closed my eyes,"she said.
"The next thing I was sitting there covered in glass and the windows were smashed."
Another student Celeste Towers, 13, was sitting next to couple of friends when she felt the impact and realised that some of her school mates had been hurt.
"One got her back hurt and another hit his head in the bar," she said.
"One had glass in their hair and one had a sore wrist."
Police are investigating whether there was a mechanical failure in the truck that may have contributed to the crash.
Other students were returned to school by bus for a debriefing and parents have been notified by the school.
Emergency services are on site and detours have been put in place to help ease one of Ballarat's busiest thoroughfares during the school pick-up time.
But VicRoads has warned drivers to expect delays through the area.