The American School Counseling Association's (ASCA) National Model has been recognized in the field of professional school counseling as an effective framework for the training and supervision of school counselor interns. Despite this recommendation, school counselor supervision models which incorporate the ASCA model have until recently been rare and are still in the early stages of development. This qualitative study describes the supervision experiences of six pairs of school counselor supervisors and their interns (at the elementary, middle, and high school levels) as they employed an ASCA-based school counselor specific supervision model in their internship practices. The supervision model utilized in this study is entitled the Professional School Counselor Supervision Model (PSCSM) and is accompanied by a reflective log on which interns recorded their activities, questions, concerns, strengths, and, once supervision had occurred, their understandings gained from their supervision sessions. Participants were trained on the model and used the model and log for a minimum of 6 weeks. Individual, audiotaped interviews were conducted with each participant, followed by a conjoint interview with the supervision-intern pair. Within-cases and cross-case qualitative analyses were performed, and a devil's advocate was used to enhance the trustworthiness of the findings. One of the key findings from this study was the positive influence that the use of the model had on participants' formal supervision sessions. Use of the PSCSM and log increased participants' self-reflections; encouraged in-depth discussions; added structure; provided opportunities for interns to ask questions and receive answers; increased the frequency of formal supervision sessions; assisted supervisors in the processing of intern strengths, weaknesses, and on-site problems; and encouraged more intern input and sharing. These positive influences also served to strengthen the supervisee/supervisor relationship. Study findings suggest that use of the PSCSM and log positively enhanced participants' professional development and served to educate participants on the ASCA National Model. Participants also provided feedback on the model and log. Implications of the findings for school counselor educators and for professional school counselors are presented. Additionally, limitations of the study are described and recommendations are made for future research related to the supervision of school counselor interns. [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.]