The moment an out-of-control semi-trailer hit a fallen tree branch and narrowly missed other vehicles in Victoria's south-west has been caught on dash cam.

In the video, released on Tuesday, a truck driver can be seen stopping to help a woman who had also hit the branch on a narrow road near Carlisle River.

As the two were talking, the semi-trailer can be seen careening around the corner, crashing through the fallen branch.

The semi-trailer then narrowly missed the other truck and hurtled towards where the woman was parked.

The woman was not injured but her car was badly damaged, Dash Cam Owners Australia said on its Facebook page.