Fatality risk in passenger cars according to seating position (front versus rear; left versus center or right) was examined using Fatal Accident Reporting System (FARS) data for 1975 through 1985. Comparing the fatality risk of unrestrained occupants matched in sex and age (within three years) revealed effects attributable to seating position, and not to occupant characteristics correlated with use of different seats. Fatality risk to drivers was the same as fatality risk to right front passengers to within 1 per cent; this was so for crashes in all directions and for frontal crashes. Fatality risk in rear seats was (26 +/- 2) per cent lower than in front seats, and lower in center compared to outboard seats by (22 +/- 4) per cent for front seats and (15 +/- 4) per cent for rear seats. The center rear seat was associated with the lowest fatality risk.