This qualitative study explores the leadership behaviors of system leaders and best practices of high school counselors in highly effective school districts that prepare all students for college and career readiness. A total of twelve participants were interviewed for this study including superintendents of schools, high school principals, and high school counselors in four, highly effective school districts in upstate New York. This study found that system leaders play a critical role in creating a district mission and vision that focuses on preparing all students for college and careers. System leaders in these highly effective districts collaborate with a variety of stakeholders in creating measureable goals, continuously gather feedback and monitor results, and develop a wide array of academic programming that is focused on providing all students with the opportunity to achieve their academic and career aspirations. System leaders allocate district resources to support programs and services that provide academic rigor and career relevancy. System leaders ensure that that all students have access to a high quality and effective comprehensive school counseling program that is led by certified school counselors who maintain a student caseload at the recommended ratio of 250:1. Superintendents and principals network and collaborate with their BOCES, local businesses, colleges and universities, and elected officials to create partnerships and support programs that prepare all students for college and careers. High school counselors in these highly effective districts have clearly defined roles and responsibilities that focuses their attention on developing positive working relationships with all stakeholders and supporting their student's academic, social/emotional, and career development needs. Counselors in these highly effective high schools have implemented a comprehensive school counseling program based on the American School Counseling Association's national model and rely on the use data to monitor student progress and to assess the effectiveness of their counseling program. This study concludes with recommendations for all school districts to be required to file their comprehensive school counseling plans with the State Education Department for consistency and accountability purposes, continuing the efforts of providing all students with multiple pathways to graduation, bringing consistency to school counselor certification programs, creating district level school counseling advisory councils to monitor and provide feedback on the effectiveness of programming, and promoting professional development opportunities for both system leaders and school counselors to fully support the implementation and evaluation of comprehensive school counseling programs so all students who attend these schools have the opportunity to be college and career ready. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]