This mixed-methods research study examined the perceived efficacy of multiweek, immersive, experiential, in-person executive education for developing EI in senior executives for improved leadership effectiveness. Extensive research supports the ability of adults to develop EI competencies through workplace training, executive coaching, and MBA programs. However, more research was required regarding the efficacy of multiweek, immersive, experiential, in-person executive education for developing EI in senior executives. Data was collected using a 12- question Likert scale survey based on the Emotional Social Competency Indicator (ESCI) measurement tool to obtain data on the perceived changes in leadership effectiveness related to the twelve EI competencies measured by the ESCI. In addition, study participants participated in semistructured interviews focused on workplace scenarios that occurred pre- and post-intervention to evaluate their responses. The survey results suggest a significant change in the relationship management domain, and the results of the thematic analysis of the semistructured interviews suggest multiweek, immersive, experiential, in-person executive education programs may be effective in developing EI competencies in senior executives. [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.]