The challenge that Tarasoff poses to mental health professionalism is that if practitioners wish relief from legal liability for failure to predict dangerousness, they must define their professional skills to exclude that predictive capacity and recognize the limitations this imposes on the scope of legitimate professional practice and claims to expertise. Such an exclusion raises public policy issues because a marked degree of public reliance has come to be placed on this predictive capacity, as evidenced in professionals' roles as expert witnesses. The major areas in which professionals have exercised a predictive role include civil commitment proceedings; in fulfilling their duty to warn; in drafting and contesting presentence reports, in sentencing, bail, and parole hearings; and in performing direct and indirect policing functions. Two policy options are available for reconciling the reliance on such predictions with professional disclaimers of a predictive capacity: (1) that 'dangerousness' be recognized as a legal status, rather than a psychiatric condition and (2) that it be determined by due process of law. 109 footnotes and 35 references.