A broad spectrum behavioral assessment and treatment package was utilized with two individuals who met DSM-III criteria for a diagnosis of posttraumatic stress disorder (PTSD) related to transportation accidents. Individualized tripartite (behavioral, cognitive, psychophysiological) assessment procedures revealed differential arousal across response systems and subjects, as well as modest pretreatment and posstreatment differences in reactivity to trauma-relevant stimuli compared to control stimuli. The behavioral treatment packages were effective in decreasing both subjects' self-monitored symptoms of PTSD. Implications of these data for assessment and treatment of PTSD following transportation accidents are discussed. © 1985 Association for Advancement of Behavior Therapy. All rights reserved.