This review aimed to identify factors associated with seeking treatment from mental health services after a traumatic event. Databases of literature were searched in a systematic manner and 24 relevant articles were found. Although many of the findings are inconsistent, the most important factors associated with treatment seeking appear to be a higher level of psychopathology, the type and level of the traumatic event, and sociodemographic characteristics, in particular female gender. Even though the evidence is insufficient to guide service development, suggestions for future research are made. The methodological quality of research should be improved to establish whether the inconsistency of findings reflects methodological artefacts or true differences between different samples and contexts.