Investigators say 41-year-old Colin Volpe was walking in the road outside the crosswalk on Blackstone and Holland, just north of Ashlan around 5:30 pm.
A person driving a van hit the pedestrian while trying to swerve out of the way.
That driver stayed at the scene to help with the investigation, but police say another car also struck the man and then drove away.
Witnesses describe the second car as a silver 4-door vehicle.
Officers are asking that person to come forward so they can get a statement about what happened.