The new phenomenon of clinical ethics is analyzed from a role theoretic perspective that differentiates consulting, teaching, watching, and witnessing. Teaching and consulting are seen as main role alternatives in clinical ethics practice, with watching and witnessing defining transitional states that reveal the complexity of clinical ethics. The problem of the legitimation of clinical ethics is discussed in terms of legal, professional, and social accountability and authorization. It is argued that the problem of legitimation is tied up with the related issue of expertise that, in turn, reflects the complex role alternatives of consulting, teaching, watching, and witnessing. Finally, the question of methodology and practice of clinical is explored in connection with the four role alternatives delineated. © 1990.