Background Understanding of the psychological impact of politically motivated violence is poor. Aims To examine the prevalence of post-traumatic symptoms subsequent to the 'troubles' in Northern Ireland. Method A telephone survey of 3000 adults, representative of the population in Northern Ireland and the border counties of the Irish Republic, examined exposure to political violence, post-traumatic stress disorder (PTSD) and national identity Results Ten percent of respondents had symptoms suggestive of clinical PTSD. These people were most likely to come from low-income groups, rate national identity as relatively unimportant and have higher overall experience of the. troubles' than other respondents. Conclusions Direct experience of violence and poverty increase the risk of PTSD, whereas strong national identification appears to reduce this risk.