Includes bibliographical references (pages [686]-701).The purpose of this qualitative grounded theory study was to explore ethical decision-making patterns of practicing professional counselors encountering boundaries of competence concerns. The study focused on boundaries of competence and ethical decision making. Using a random selection process, 725 licensed counselors in the state of Illinois were sent invitations to participate in the study. A total of 33 counselors responded to the invitations. Fourteen licensed counselors were selected to participate in the study. The primary research tool was a four-phase, faceto- face interview, which used a conceptual mapping exercise. The conceptual mapping exercise yielded very rich data. During the conceptual mapping exercise, participants were asked to present a clinical case where, in the process of individual therapy, a boundaries of competence concern had emerged. After participants had selected and reviewed the relevant client case, they were asked to create a conceptual map spatially representing their process of decision making. A research-based model for ethical decision making in boundaries of competence concern situations emerged out of the research data. No other researchbased model or models specific to boundaries of competence concerns were found in the literature. It is therefore assumed that the emergent model is the first researchbased model for ethical decision making to be presented to the profession. It is also assumed that this is the first model specifically addressing boundaries of competence concern situations to be developed. Many implications for counselors, supervisors, and counselor educators regarding the ethical decision-making process emerged from the data. Implications included consideration of a number of factors within the ethical decision-making process. These factors emphasized: (a) more direct consideration of the therapeutic relationship, (b) the potential impact of negative supervision and/or system dynamics impacting the decision-making process, (c) training and consideration for the possibility that clients will terminate the treatment process without allowing space and time for closure to the relationship, (d) the aftermath/post-outcome reflection stage as a potentially painful process, which may need specific attention by supervisors and counselors, and (e) consideration of the conceptual mapping task as a possible training, supervision, and research tool.Ed.D. (Doctor of Education