This research argues that establishing and sustaining leadership diversity within Higher Education Institutions (HEIs) is a complex-systems challenge and that those responsible for leading efforts to establish and sustain diversity, referred to as DEI leaders, should adopt a mindset of systems thinking and apply problem-solving methods and tools informed by systems thinking. Semi-structured interviews with DEI Leaders at HEIs were conducted regarding background and perceptions of their work, and how they thought about and made choices concerning diversity challenges. Interview questions were designed to gain an understanding of the degree to which these leaders think about DEI and if they approach these problems from a systems perspective and use system-informed methodologies and tools. Results indicated that DEI leaders acknowledged diversity to be a challenging problem but there was little understanding that this kind of problem was either complex or systemic. Furthermore, DEI leaders relied on conventional linear formulations and problem solving because they did not know how to think in systems or use methods and tools derived from this mode of thinking. Implications suggest that those responsible for leading efforts to establish and sustain diversity within HEIs rely on methodologies and tools which are insufficient to solve complex DEI problems. Recommendations are made for education to help DEI leaders to adopt a mindset of systems thinking and apply problem solving methods and tools informed by this mode of cognition
