Recent research has shown that there is a positive relationship between insecure attachment and psychopathology (van IJzendoorn, Bakermans-Kranenburg & Juffer, 2008). However, there is little evidence for the effect of attachment on emotion regulation of traumatic stress. In my first study I examined whether the following variables were protective or risk factors for PTSD or facilitators of posttraumatic growth: adult attachment dimensions, early traumas, self-esteem, and posttraumatic cognitions. I found that individuals with more early traumas, high attachment anxiety, low self-esteem and more negative posttraumatic cognitions exhibited more PTSD symptoms. Furthermore, there was a positive association between low attachment avoidance and posttraumatic growth and between PTSD and PTG. In the second study, I adopted a psychobiological perspective to investigate the effect of oxytocin and secure attachment priming in emotion regulation of trauma in an analogue trauma paradigm (using trauma films). I found that those in the secure versus control neutral prime condition reported more felt-security and happiness. However, both secure priming and oxytocin did not reduce negative mood, trauma intrusions and heart-rate following the trauma film clips. Both studies provide support for the effect of attachment in emotion regulation of traumatic stress