Employers' duties of care under both common and statute law include the need to take reasonable care of the health and safety of the workforce. This includes both the moral and legal duties to consider the psychological needs of personnel following exposure to traumatic events related to the workplace. While this has been recognized within many high-risk occupations such the police, fire and rescue services and the military, there is also evidence that post-trauma support in the workplace is increasingly commonly provided not only among health and social services agencies, but within many private sector organizations. Over the past decade, however, there has been considerable controversy over the provision of early psychological support to personnel in the form of critical incident stress management (CISM) processes. In particular, one aspect of CISM, the use of psychological debriefing (PD) has come under scrutiny and criticism as two studies indicated that PD was ineffective and had the potential to do harm. Inevitably, this has provoked much uncertainty and confusion among some organizations as what should be the most appropriate support. It has also led to misconceptions and misunderstandings as to the aims and purpose of PD, together with inaccuracies of terminology, for example describing PD as 'counselling'. Despite the controversy, both CISM and PD continue to be provided on a widespread basis, often utilizing a framework of voluntary peer group support. This paper intends to (i) present a review of the current status of CISM practices, including the use of PD within various organizations in the UK and (ii) provide a clear framework and understanding of the main issues and to clarify conceptual misunderstandings. The history, principles and background of the use of post-trauma support in the workplace, charting trends over the past two decades, previous research, problems with the evidence base and current thinking and practice in the field are reviewed. The relevance and implications of the National Institute for Clinical Excellence Guidelines on the Assessment and Management of Post Traumatic Stress Disorder, which make recommendations for early interventions for post-traumatic stress disorder are discussed. Reference is made to the use of CISM and PD within both statutory and voluntary organizations in an international context.