In this literature review, the author focuses on several ethical considerations in case conceptualization and diagnosis, including diagnostic training and competence. Meeting the American Counseling Association's (1995) ethical standard for diagnostic training has several ethical implications for counselors, counselor educators, and supervisors. For counselors who struggle with how to meet their ethical responsibilities in diagnosis but who want to remain true to their developmental counseling emphases, the author discusses some of their concerns, the implications of and possible approaches to this aspect of their work.