AbstractThis study examined the contribution of complex posttraumatic stress disorder (PTSD) diagnosis and symptomatology to the difficulties of anger, aggression, and self‐harm in a Northern Ireland clinical community sample. A “current complex PTSD” (CCPTSD) group (n=11) was compared with a “current PTSD” group (n=31) on self‐report measures of these variables. The CCPTSD group demonstrated significantly higher levels of physical aggression and self‐harm than the PTSD group. The complex PTSD symptom of ‘alterations in self‐perception’ was a significant predictor of aggression and history of self‐harm, suggesting the potential role of posttraumatic shame and self‐loathing in PTSD theoretical models of these destructive behaviors. Social desirability was a notable confounding influence in the assessment of anger, aggression, and self‐harm in traumatised individuals. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–16, 2009.