Motor vehicle traffic fatalities in the United States are described by two major data sources, the Fatal Accident Reporting System (FARS) and the National Center for Health Statistics Multiple Cause of Death data (NCHS). Certain data, such as the age and sex of the fatality, are reported by both sources. However, each source contains data absent from the other. For example, only the FARS describes the precise circumstances of injury, and only the NCHS identifies the anatomic injuries listed on the death certificate. Thus, it would be useful to have a single file that offers for each case all of the data provided in each of the separate files. Creation of such a file is impeded by the fact that neither file contains personal identifiers for the cases listed. The present paper describes a method of matching cases from the two files based on simultaneous agreement of several variables common to both files (age, sex, date of death, role in the crash, and state in which the injury occurred). Using this method, 85% of the FARS cases can be uniquely matched with a case in the NCHS data.