Purpose: The purpose of this mixed methods study was to investigate the best practices for bullying interventions. The participants for the quantitative data collection were counselors (n = 22) and principals (n = 20) located in elementary and junior high schools; 10 were selected to participate in the qualitative data collection. Method: The Bullying Survey (Robles-Pina, et al., 2004) was used for collecting the quantitative data and The Protocol for Collecting Qualitative Data (Tracy, 2010) using Bandura's four self-efficacy processes, was used to collect qualitative data. Quantitative data were analyzed using one-way and two-way MANOVA statistical analyses and qualitative data were analyzed using theme analysis. Findings: Statistically significant differences with a large effect size were found between elementary principals and junior high principals with elementary principals more likely to endorse the need for a school-wide bullying plan and the use of websites, books, and videos as bullying interventions. Moreover, statistically significant differences with a large effect size were found between elementary and junior high counselors. Elementary counselors were more like to endorse the following bullying interventions: (a) school need for a bullying program, (b) use of their own bullying plan, (c) reading books to students, (d) using websites, books, videos, and (e) encouraging students to talk with each other. A statistically significant interaction with a large effect size indicated that the use of bullying interventions was not solely dependent on whether the leader was a counselor or principal or whether they were located in an elementary or junior high setting, but that the use of bullying interventions was based on individual leaders' knowledge. Analysis of the qualitative data indicated the following interventions to be most frequently used: (a) providing school bullying information at assemblies, (b) anonymous reporting, (c) providing announcements, (d) visiting with parents of bully and target, and (e) talking to bully and target. Contrary to identified best practices, school guidance units and staff development were not identified. In summary, staff development should be based on present knowledge of school leaders, a school bullying plan that is based on best practices, and the developmental needs of students. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]