The National Crash Severity Study (NCSS) data file was interrogated to determine whether occupants of different statures and masses are subject to different injury severity rates. The NCSS data was divided into four height and weight categories. Injury severity rates were calculated for each category. The data was also interrogated for occupant size effects relative to frontal and side impacts, male and female occupants, use or non-use of restraints, and driver and right occupant positions. To gain further insight into the injury severity rate sensitivity relative to occupants’ statures and masses, the data was also reviewed from the point of view of body segment injury.The analysis shows little, if any, effect on the rates of injury severity due to either height or weight variations of the occupant. The evidence of no effect is very strong for frontal impacts and somewhat less for side impacts. A lower level of confidence in side impacts is caused primarily by substantial thinning out of the data at the extreme ends of the accident population distribution. Expansion of the analysis to include injury severity rates of body areas produced likewise no substantial evidence of height and weight dependency.