Scores on the Injury Impairment Scale (IIS) were compared with reported disability for work or school, household activities, and activities of daily living during the first 18 months after injury for 2,194 persons treated in an emergency department or hospitalized for their injuries. Persons whose most severe injury was more life-threatening or who had larger numbers of injuries more often had higher IIS scores for their most life-threatening injury than did persons with fewer or less life-threatening injuries. Hospitalized patients had higher IIS injuries more often than did emergency department patients. As IIS increased, duration of disability also increased. However, many high IIS patients either reported no disability or disability of only short duration, suggesting only limited association between disability and IIS as it is currently designed.