This study examined both the moral development levels using the Defining Issues Test-2 (DIT--2) and ethical decision-making using the Professional Opinion Scale (POS) of social workers who provide field supervision to students within accredited social work programs in Wisconsin. Using the moral development theory of Kohlberg (1981) which defined moral development in terms of stages that increased an individual's ability to incorporate justice reasoning, Rest (1979) developed a four component model consisting of moral identity, judgment, sensitivity and motivation; the Defining Issues Test-2 (DIT-2) is a means of measuring moral judgment. Abbott (1988) developed the Professional Opinion Scale (POS) as a means of measuring social workers' identification with the established values of the profession. Applying Rest's model, moral identity in social workers was connected to identity as a social worker. The POS was postulated as a measure of social work identity and motivation since higher POS scores are reflective of adherence to the social work values identified in the "National Association of Social Work Code of Ethics" (r2008). A web-based survey was distributed to 1356 social workers through the e-mail lists of field coordinators in accredited social work programs in Wisconsin resulting in 163 usable surveys for analysis. Results of this study demonstrate that participants who score higher on the DIT-2 also score higher on the POS supporting the postulation that higher levels of moral development relate positively to ethical decision-making. Study participants with Masters of Social Work degrees scored higher on the DIT-2 but not higher on the POS than those holding Bachelor of Social Work degrees. There were no relationships found between either DIT-2 scores or POS scores with years in service, and employer type or practice area. This study implies that the capacity to make ethical decisions can be demonstrated by higher levels of moral development and congruence with the social work values. The outcomes of this study can serve as a foundation for further research examining the fourth component of Rest's model, moral action, applied to social worker's ethical choices. [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.]