This non-experimental quantitative study utilized linear regression to examine if elementary school counselor and principal relationships predict elementary school counselors' implementation of the American School Counselor Association (ASCA) National Model. The sample (N = 163) included elementary school counselors (n = 108) and principals (n = 55) in public schools in a state in the west south central region of the United States. Using predictive design, the study sought to answer if the school counselor and principal relationship serves as a predictor of ASCA National Model implementation in order to uncover if there is a significant association between the school counselor and principal relationship and the extent of a school counselor's implementation of the ASCA National Model. The data for the research study was collected through the Principal-Counselor Relationship Rating and the School Counseling Program Implementation Survey. By examining the predictive relationship between the Principal-Counselor Relationship Rating and the School Counseling Program Implementation Survey, this study found that there is a significant association between the school counselor and principal relationship and the extent of a school counselor's implementation of the ASCA National Model. In addition to identifying that the overall school counselor and principal relationship rating does serve as a predictor of the ASCA National Model implementation, the results indicated that the "mission" and "vision" subscale of the Principal-Counselor Relationship Rating most significantly predicted school counseling program implementation. When multiple variables including the strength of the school counselor and principal relationship, years of experience, certification type, and educator type were examined, it was found that individually, the strength of the school counselor and principal relationship was the only significant predictor of ASCA National Model implementation. However, a combination of all of the variables also significantly predicted the level of ASCA National Model implementation. The findings from this research study add knowledge to the research problem and can support principals, school counselors, counselor educators, and educational leadership instructors to better prepare for effective collaborative relationships and implementation of the ASCA National Model. The findings could lead to positive outcomes in schools if educators are better prepared to serve students and schools effectively. While the results of the study add essential knowledge to the field, multiple areas for further research are suggested in order to continue to understand how to best support students through comprehensive school counseling programs. [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.]