Although information about individuals' exposure to highly stressful events such as traumatic stressors is often very useful for clinicians and researchers, available measures are too long and complex for use in many settings. The Trauma History Screen was developed to provide a very brief and easy-to-complete self-report measure of exposure to high magnitude stressor (HMS) events and of events associated with significant and persisting posttraumatic distress (PPD). The measure assesses the frequency of HMS and PPD events, and it provides detailed information about PPD events. Test-retest reliability was studied in four samples, and temporal stability was good to excellent for items and trauma types and excellent for overall HMS and PPD scores. Comprehensibility of items was supported by expert ratings of how well items appeared to be understood by participants with relatively low reading levels. In five samples, construct validity was supported by findings of strong convergent validity with a longer measure of trauma exposure and by correlations of HMS and PPD scores with PTSD symptoms. The psychometric properties Correspondence concerning this article should be addressed to Eve Carlson, Ph.D., National Center for PTSD (334-PTSD), 795 Willow Rd., Menlo Park, CA 94025. eve.carlson@va.gov. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at www.apa.org/pubs/journals/pas NIH Public Access Exposure to sudden, highly stressful events is fairly common among the general population in the U.S. (Breslau, 2002) and is even more frequent among those seeking mental health treatment (Jacobson, 1989). Information about exposure to sudden, severe stressors is clinically important because such exposure has been found to be associated with increases in later psychological disorder (Brown, Fulton, Wilkeson, & Petty, 2000;Bryant et al., 2010) and decreases in physical health (Schnurr & Green, 2004), occupational functioning (Zatzick et al., 2008), and socioeconomic well-being (Zielinski, 2009). In prospective studies and meta-analyses of trauma research, psychological disorders found to increase most following highly stressful events include depression, generalized anxiety disorder, posttraumatic stress disorder (PTSD), agoraphobia, phobia, and substance abuse (Brown et al., 2000;Bryant et al., 2010;Reed, Anthony, & Breslau, 2007). In addition, repeated, severe sudden stressors that occur during early childhood are thought to play a role in the development of borderline personality disorder (Herman & van der Kolk, 1987); some dissociative disorders (De...