This qualitative research study investigated and identified the classroom management strategies of 12 highly effective middle school teachers who served diverse student populations at two different school sites. In addition, this research explored the beliefs and experiences of 305 diverse middle school students regarding their experiences with classroom management and teachers in general and specifically with the classroom management of their very own highly effective teachers. Observational, teacher interview, and students' written response survey data were triangulated using content analysis to identify key concepts and effective classroom management strategies practiced by these highly effective teachers in diverse middle schools. The most frequently practiced classroom management strategies by highly effective teachers in culturally diverse middle schools were categorized into the three broad domains of organization, instruction, and relationship. These categorical domains align themselves readily with prevalent classroom management literature exploring these areas. Most notably are the areas of organization and relationship. Significant findings include the identification of instructional intensity grounded in explicit explanation, reflective questioning, and meeting individual student needs as a highly effective classroom management strategy, which informs all other strategies. Furthermore, relationships between the effective classroom management strategies revealed in this study and the dominant literature on effective classroom management strategies and cultural responsiveness were thoroughly explored. Evidence of cultural responsiveness was found in certain highly effective classroom management strategies. However, triangulation of the data revealed that although these teachers practiced in middle schools with culturally diverse student populations, most highly effective teachers selected specific classroom management strategies based on what they believed would increase their overall ability to maintain organized routines, to increase student engagement and achievement, to meet student needs, and to build caring relationships, instead of in response to the cultural dynamics of the diverse populations they taught. [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.]