Injury scaling as a means for classifying the extent of trauma has a long history. Joint medical-engineering activity related to motor vehicle crash injury research, however, did not formally begin until 1967. Four years later, the first Abbreviated Injury Scale (AIS) was published.During the past ten years, the AIS has undergone four revisions, the most significant one in 1980. Several major problem areas, especially related to coding brain injuries, have been resolved successfully. Areas still requiring study are training needs for AIS users; sources of injury data; and comparability of the AIS with other injury classification systems.