While student achievement is only one indicator of a building principal's effectiveness, it is widely considered to be one of the most important. This is especially true in regard to the current climate of accountability surrounding education. Multiple studies have yielded results concerning the behaviors and characteristics of building principals who are effective at increasing student achievement. However, many of these studies have not been able to show a direct and substantial connection between specific behaviors or traits and student achievement. The definition of emotional intelligence provided by Salovey and Mayer (1990) can be interpreted to encompass a range of these previously studied abilities under the umbrella of a distinct intelligence. This study incorporated the use of a hierarchical regression model, in order to determine the amount of variance in student achievement that can be accounted for by a principal's measured emotional intelligence or EQ. The use of EQ as an omnibus test of principal traits has the potential to inform both pre-service training for aspiring principals and professional development for current administrators. Results of this study indicate that there is a small, but statistically significant effect of a building principal's emotional intelligence on student achievement in the areas of communication arts and mathematics. [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.]