This text is an introduction to complexity theory and its application to public services management. In a clear and comprehensible manner it: argues that the complexity of the public policy process limits the usefulness of the 'new public management' approach; challenges management techniques used in key areas of the public sector, such as performance management, staff development leadership, strategic management and the use of IT; and proposes alternative approaches that are based on a correct understanding of the disorder in the policy process.The difficult concepts of complexity theory are presented in an accessible manner that explains the central concepts in this new approach to social science. The relevance of emerging theories like knowledge management, emotional intelligence and risk management, are also explored. It is suitable for public service managers and professional in all areas, MBA and postgraduate students in public service management and public policy, undergraduate students in applied social science, policy and politics.