The impact of traumatic events and the experience of psychological trauma have been depicted in myth, legend, art and literature throughout human history (for instance [1,2]). They have, for the last generation, been psychiatrically classified as post-traumatic stress disorder (PTSD) and as acute stress disorder (ASD). The papers in this In-Depth Review serve both to describe the status of current thinking in regard to the scientific conceptualization of psychological trauma and to raise questions in regard to our understanding of the contextualization of traumatic experience within occupational settings. For many years, occupational medicine and health and safety legislation has focused upon observable injury and illness caused by single events. These articles play a timely role in reminding us that many health and welfare concerns with far-reaching effects within organizational environments may be psychological, social and complex in nature and have enduring effects over a considerable span of time. In the first paper, Bisson [3] introduces the diagnostic categories of PTSD and ASD and presents an overview of the characteristics of the Diagnostic and Statistical Manual of Mental Disorders and International Statistical Classification of Diseases and Related Health Problems [4,5], describing prevalence and risk factors in the development of traumatic symptoms. The variation in diagnostic features between these two classification systems serves to illustrate the ongoing development and refinement of our contemporary understanding of traumatic experience. Bisson signals our increasing awareness of resilience as opposed to the pathology of trauma. The concept of a resilience trajectory may challenge the reader to query whether employee resilience can be strengthened through processes of selection, screening and organizationally based support systems. These issues are addressed and developed in the following papers. While the first article focuses upon individual outcomes of treatment, Bisson suggests that individual prediction of risk is indeed a poor predictive tool and stresses that the degrees of support, connection and affirmation within the organizational context will contribute to recovery. Using the National Collaborating Centre for Mental Health Guidelines for intervention (the development of which he played a significant part), Bisson briefly considers the viability of particular interventions. He signals the issues concerning early intervention in the workplace that the following articles then address. In particular, he stresses that the emotional component of single-session interventions termed as psychological debriefing (PD) should be avoided, suggesting that in many situations practical and pragmatic support provided by an informed peer group is both necessary and sufficient an intervention. Utilizing their extensive experience in Australia, McFarlane and Bryant [6] then focus specifically upon the impact of trauma in occupational settings acknowledging that individuals and groups within some occupations and workplaces experience higher risk factors than others. They introduce notions of cumulative risk and secondary stressors and suggest preventive or minimization strategies for the management of trauma within the workplace. Management strategies such as systematic assessment, reduction of exposure and rotation of duties are noted alongside the repetition of Bisson’s caution that there is inherent difficulty in providing accurate and ethical prediction of risk on an individual basis. They suggest that employers and supervisors nevertheless have a duty of care to identify and support those individuals adversely affected by traumatic events. The authors raise issues of legal and employer liability and financial compensation, a key factor in the ongoing debate about effective support for workers. Such risks are balanced against acknowledgement of the financial costs of providing support systems and the necessary cost-benefit analysis evaluation of any intervention adopted by an organization. They argue that early intervention or treatment to prevent further injury is crucial. The need for an evidence-based choice of intervention is stressed, an issue of particular importance in evaluation of PD and other structured interventions. Their acknowledgement of cumulative effects and potential sensitization to recurrent occupational stressors signals a need for occupational health practitioners to remain aware of the latest research in regard to complex PTSD and to constructivist interpretations of the relationship between cumulative stress and traumatic events. c/o School of Applied Psychosocial Studies, Faculty of Health and Social Work, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.