This study examines injuries occurring in fully restrained (Lap/Torso belted) occupants of passenger vehicles involved in collision in the region of London, Ontario during a twelve month period 1 May 1976 to 30 April 1977. 125 collisions involving 157 fully restrained occupants were studied in regard to the collision forces involved and the mechanisms of injury to these occupants. Twelve occupants involved in nine of these collisions sustained serious, critical or fatal injuries (AIS 4, 5, & 6). These cases are recorded in detail and parameters studied include: faulty seat belt function, location of major vehicle impact, degree of intrusion into the occupant space and ejection of occupants. 145 occupants involved in 120 of these collisions sustained injuries of lesser severity (AIS 0 to 3). These cases are reviewed with regard to the above parameters and also regarding points of contact in the vehicle leading to occupant injury and body regions commonly injured.