The aim of the current study was to investigate the relationships between self-consistency, trauma-themed self-concept and PTSD symptom severity. Participants (N = 97) completed the Centrality of Event Scale, a measure of self-consistency and the Posttraumatic Diagnostic Scale. As previously found, trauma-themed self-concept was found to be positively associated with PTSD symptom severity. Self-consistency was found to be negatively associated with PTSD symptom severity and trauma-themed self-concept. Mediation analyses indicated that trauma-themed self-concept mediated the relationship between self-consistency and PTSD symptom severity. The findings suggest that self-consistency is related to better posttraumatic psychological adjustment.