In examining predictors of posttraumatic stress, researchers have focused on trauma intensity and devoted less attention to other variables. This study examined how personality and demographic variables are related to the likelihood of experiencing a trauma, and to the severity of posttraumatic symptoms in a sample of 402 college students reporting a wide range of trauma. Elevations in antisocial and borderline traits were significant predictors of retraumatization, accounting for 12% of the variance. Personality variables and trauma intensity were significant predictors of PTSD severity, accounting for 43% of the variance. Neuroticism interacted with trauma intensity in predicting Posttraumatic Stress Disorder (PTSD) severity. Among persons low in Neuroticism, there was a modest trauma intensity—PTSD relationship, whereas among persons high in neuroticism there was a strong relationship.