An elderly woman was is in a serious but stable condition in Noble's Hospital, following a crash near Ballasalla.
She was in a silver Toyota Auris which collided head on with a yellow Volkswagen van, at Ballawhetstone on the Southern 100 course.
Police want to hear from anyone who witnessed the incident, or saw either of the vehicles before it happened.
It's understood a bin wagon was stopped in the area at the time, which led to a number of vehicles heading towards Cross Four Ways having to wait.
Anybody with information is asked to ring Port Erin police, on 832222.
The accident happened just before 8am today (Wednesday).