There is a pressing need for public administration leaders to exhibit expertise-based intuitive leadership traits for developing countries to respond to sustainability challenges. While the importance of explicit and tacit knowledge to underpin expertise-based intuitive decision-making is known, public service leaders of developing countries can lack these traits. It is necessary to explore the reasons for leadership skills gaps in order to define remedial actions, such as better executive development training. This study conducts 28 in-depth interviews with public administration leaders, managers, and executive training professionals in Pakistan to address the challenge of how to build expertise-based intuitive leadership traits in public administration leaders. The main findings highlight deficiencies in domain-specific knowledge and soft skills. Deficits in the formal training of leaders and the negative contribution of cultural preconditions both result in explicit and tacit knowledge gaps that undermine expertise-based intuitive decision-making. An “iceberg of expertise-based leadership” model is conceptualized, extending on previous models, to describe the intangible role that explicit and tacit knowledge play in the visible expression of leadership skills. The relevance of this model for the success of public sector-led initiatives for sustainable development is highlighted.