The 1980 and 1985 versions of the Abbreviated Injury Scale (AIS) are quantitatively and qualitatively compared based on experience gained during the recent coding of nearly 115,000 injuries from more than 33,000 seriously injured patients using both AIS versions. Quantitative comparisons are based on differences in AIS scores and Injury Severity Score (ISS) values which result under the two schemes. Qualitative comparisons concern the completeness and clinical usability of the two scales in a trauma center setting.