INTRODUCTION: This study investigated the prevalence of post-traumatic stress symptoms among professional ambulance personnel in Sweden and investigated the question: "Does self-knowledge have influence on how well one copes with the effects of daily work exposure from such events?" Little is known about the variables that might be associated with post-traumatic stress symptoms in high-risk occupational groups such as ambulance service groups. METHODS: Data were gathered from ambulance personnel by means of an anonymous questionnaire. Survey responses of 362 ambulance personnel from the county of Västra Götaland were analyzed. A correlation was established between post-traumatic symptoms using the impact of event scale (IES-15) and the Professional Self-Description Form (PSDF). RESULTS: Of those who reported a traumatic situation, 21.5% scored > or =26 on the IES-15 subscale. Scores >26 indicate "PTSD caseness". There were significant differences on PSDF subscales between those presenting with or without post-traumatic symptoms. CONCLUSIONS: The mental health and emotional well-being of ambulance personnel appear to be compromised by accident and emergency work. The high prevalence of PTSD symptoms in ambulance personnel indicates an inability to cope with post-traumatic stress caused by daily work experiences.