Wiltshire Police attended a road traffic collision involving 13 vehicles on the M4 at about 3.15pm yesterday.
Both lanes of the carriageway were closed, between Membury Services and J14, to allow emergency services, including an air ambulance to attend.
There were no reported serious injuries.
A total of three patients were attended to by paramedics at the scene, with their injuries assessed as not life threatening or life changing.
One patient had to be freed from their vehicle by the fire service using cutting equipment.
The westbound and eastbound carriages have reopened at 5.30pm.