This comparative case study examines the influence of ethics education on moral reasoning among pre-service teacher preparation and social work students. This study specifically investigates the ethical values of students enrolled in a teacher preparation and social work education program by their fourth year of study; the degree of ethical knowledge of social work and teacher preparation students by their fourth year of study; the program values in the social work and teacher preparation programs; the similarities and differences in how teacher preparation students and social work students reason through moral dilemmas; and the formal ethics training of students in each program by their fourth year of undergraduate education. In looking at teacher preparation and social work education, differences in student and programs values were identified. This study revealed that students enrolled in teacher preparation displayed a wider variance in value identification compared to students enrolled in social work. Further, teacher preparation students' values were more individualistic and rule oriented in orientation whereas social work students often identified with values that are relational in nature. This study also revealed that social work students were familiar with the National Association of Social Workers (NASW) Code of ethics; however, students in teacher preparation reported minimal discussion of ethical terminology or codes of ethics in their coursework. Further, students in teacher preparation reason through ethical dilemmas adhering to either an ethic of care or an ethic of justice orientation as described in the Shapiro and Stefkovich (2011) framework for ethical decision-making and a Stage Three from Kohlberg's Theory of Moral Development (1975). Many students in teacher preparation expressed a preoccupation with rules and policy compared to students in social work. In comparison, social work education students often reason through ethical dilemmas from an ethic of care, founded in relational values such as compassion and helpfulness. Further, from Kohlberg's Theory of Moral Development, social work students' predominately reasoned from a Stage Four. This study also revealed that students' reason from a higher level when the ethical dilemma was professionally related and lower when the dilemma was professionally neutral. The findings of this study contribute to the body of literature surrounding ethics education in professional development and higher education, the use of formal codes of professional ethics, and moral reasoning and decision making in professional development. Lastly, several suggestions for future studies are proposed that include a longitudinal study that compares students from year one to year four in a range of different areas of professional education. Second, a future study should look into other variables that impact moral behavior beyond moral reasoning, such as moral sensitivity. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]