This quantitative study investigated the ethical decision-making process of 177 Missouri members of the American Association for Marriage and Family Therapy using two in-session duty-to-warn scenarios of child abuse and HIV transmission. The components of the critical-evaluative level of ethical decision making include the lower-level decision components of personal/therapeutic response, professional ethics, and legal considerations/laws of the State, and the components of the higher-level decision base, the meta-ethical principles, which are nonmaleficence, autonomy, beneficence, fidelity, and justice. Statistical results indicated that in the child abuse scenario, professional ethics and legal considerations/laws of the State were considered most important, whereas in the HIV scenario, professional ethics were the preferred lower-level decision base. Across scenarios, the preferred higher-level decision base was nonmaleficence. There were differences across the child abuse and HIV scenarios in the perceived significance of the remaining lower-level decision base items as well as differences in perceived significance and ordering of the remaining meta-ethical principles. Limitations are discussed.