Treating psychiatrists may precipitously and unwittingly be thrust into the role of expert witness because of certain actions they may take on behalf of their patients and may suffer adverse consequences as a result of lack of training and experience. The authors review this problem and suggest means of avoiding the pitfalls involved. Recommendations include warning patients of the uses that will be made of communications between their treaters and third parties, recording the sources of clinical data for use in communications with the legal system, separating the roles of treating psychiatrist and expert witness, and consulting with attorneys or experienced forensic practitioners.