An elderly woman has died after being hit by a three-wheeled motor scooter.

Police say the yet-to-be identified pedestrian, believed to be aged in her 80s, was struck by the road-registered scooter as she crossed South Road in Braybrook with her shopping trolley, just before 1pm on Wednesday.

The scooter involved in the fatal incident in Braybrook. Credit:Eddie Jim

Sergeant Marty Wallace, from the Westgate Highway Patrol unit, said police were still trying to determine the details of the fatal incident.

"We're still investigating at this stage," Sergeant Wallace said.