As the need for new leaders has increased, so has the need for new and more effective forms of leadership development (Hamel, 2007; Lojeski, 2010; Gratton, 2011). Action learning has been popularized as one of these new forms of leadership development (Peters & Smith, 1998; Byrnes, 2005; ASTD, 2008; Trehan & Pedler, 2011). However, empirical research on the relationship between action learning and leadership development is only just beginning (Marquardt, et. al., 2009; Leonard & Marquardt, 2010). Given that action learning theory evolved out of practice, researchers are now trying to uncover governing variables that account for the observed practice effect (Leonard & Marquardt, 2010). In an effort to systematize the action learning methodology with consistent professional standards, the World Institute of Action Learning (WIAL) has provided a six-component model of action learning for program coaches and designers (Marquardt, 2004; 2011; WIAL, 2013). However, action learning, by definition, is based on the real and timely problems of an organization (Marquardt, 2011; WIAL, 2013) and therefore there is significant variety in how these programs are implemented. Given these complexities, it is unclear which specific program factors may impact the leadership development of participants. This study attempts to identify those factors by using an exploratory qualitative methodology informed by Moustakas (1994), Patton (2002), and Creswell (2012). Twelve action learning participants in three action learning programs were interviewed and their responses were analyzed by using a reductive thematic analysis. This study found that two programs were effective in stimulating leadership development outcomes in participants. Participants in the third program showed less certainty and consistency in their responses. Across all three action learning programs, participants showed improvements in self-confidence, problem-solving, expanded professional network, coaching skills, and listening. The most significant program factors leading to these outcomes were the program coach, program maturity, problem type, intended program outcome, group diversity, and the group questioning process. Implications for theory and practice and recommendations for future research are included. [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.]