The recognition of tensions, contradictions and paradoxes in theory, research, and practice within organisations is important for effective organisational leadership (EOL). The extent to which managers and policy makers currently have adequately come to terms with such complexity still remains open to discussion. The wicked problem construct (WPC) is a concept, process and a framework that can be used in identifying the reasons for these tensions and contradictions, explaining how they can be managed, and pointing out the limits they create for what is needed for effective organisational leadership. This paper examines the conceptual literature on 'wicked problems', identifying the critical dimensions of the proposed construct, and exploring the lack of attention to nonlinear epistemology of practice and systems thinking by managers and policy makers. The challenges of traditional management approaches to address complexity and to increase effectiveness in dealing with wicked problems are explained. The implication for practice of the WPC as a framework for organisational effectiveness in public, private, and the third sectors is described.