In Finland during the period 1972-1983, there were 3,564 severe traffic accidents involving one or more victims dying within 30 days of the accident. Forty-two of the victims had been wearing a seatbelt and had an abdominal trauma as the main cause of death or as first diagnosis of injury. Small intestine and colon injuries were more common in the severely injured victims than was the case with the fatally injured ones and in these accidents the injury mechanism was always deceleration or contusion, which was in most cases caused by the seatbelt. Liver injuries seem to be the major abdominal cause of fatality, and in the fatally injured group, half of the victims sustained the fatal abdominal injury through gross crushing impact. When the direction of the impact was analyzed, all the victims seated on the receiving side of the vehicle in lateral impact collisions sustained an abdominal injury with fatal outcome. It seems that the seatbelt is less effective in protecting wearers from severe or fatal abdominal injuries in lateral impact collisions.