There is a growing movement to define competency within the field of marriage and family therapy (MFT), particularly with respect to the training of practitioners and the evaluation of clinical practice. Efforts to define competency, however, transcend the practice of MFT and much can be learned from the experiences of other disciplines. Professions such as education, law, and medicine have made strides toward addressing the complex issue of competency standards in their respective fields. This article describes some ways in which the issue of competency has been approached in other professions, as well as some common dilemmas posed by adopting a competency-based orientation, to shed light on the process of defining competency in MFT. Moreover, this article identifies some of the more useful conceptualizations, modes of pedagogy, and evaluative practices found in other professions.