OBJECTIVE We examined the prospective influence of the resilient, undercontrolled, and overcontrolled personality prototypes on depression and posttraumatic stress disorder (PTSD) symptoms among Iraq/Afghanistan war veterans. After accounting for the possible influence of combat exposure, we expected that the resilient prototype would predict lower depression and PTSD over time and would be associated with adaptive coping strategies, higher social support, lower psychological inflexibility, and higher self-reported resilience relative to overcontrolled and undercontrolled prototypes, independent of traumatic brain injury (TBI) status. METHODS One hundred twenty-seven veterans (107 men, 20 women; average age = 37) participated in the study. Personality was assessed at baseline, and PTSD and depression symptoms were assessed 8 months later. Path analysis was used to test the direct and indirect effects of personality on distress. RESULTS No direct effects were observed from personality to distress. The resilient prototype did have significant indirect effects on PTSD and depression through its beneficial effects on social support, coping and psychological inflexibility. TBI also had direct effects on PTSD. CONCLUSIONS A resilient personality prototype appears to influence veteran adjustment through its positive associations with greater social support and psychological flexibility, and lower use of avoidant coping. Low social support, avoidant coping, and psychological inflexibility are related to overcontrolled and undercontrolled personality prototypes, and these behaviors seem to characterize veterans who experience problems with depression and PTSD over time. A positive TBI status is directly and prospectively associated with PTSD symptomology independent of personality prototype. Implications for clinical interventions and future research are discussed.