Investigators have recently identified a two-factor structure underlying posttraumatic stress symptoms through the use of exploratory factor analysis. [Taylor et al. (1988). The structure of posttraumatic stress symptoms. Journal of Abnormal Psychology, 107, 154-160]. These two factors, which were labeled as Intrusion and Avoidance, and Hyperarousal and Numbing, are consistent with current theoretical models of posttraumatic stress disorder--PTSD [e.g. Foa et al. (1992). Uncontrollability and unpredictability in post-traumatic stress disorder: An animal model. Psychological Bulletin, 112, 218-238]. However, the authors of the Taylor et al. study issued caution in interpreting their findings because there has yet to be a systematic replication of their results. This paper presents a confirmatory factor analysis of the two-factor structure of posttraumatic stress symptoms in 217 survivors of serious motor vehicle accidents with varying degrees of PTSD symptoms. A hierarchical, confirmatory-factor analysis conducted with a structural equation modeling statistics package confirmed that the model proposed by Taylor et al. can adequately account for the presentation of PTSD symptoms in this sample of motor vehicle accident survivors. The implications for the assessment and diagnosis of PTSD are discussed.