summarize: This paper traverses the domains of leadership and decision-making within various types of systems with different levels of complexity. The article presents some background about both leadership and decision-making, and then explores the concept of leadership decision-making and some of the factors involved. The paper then reviews complex systems and provides examples to differentiate complex systems from other systems. Finally, these strands are brought together with a consideration of leadership decision-making in complex systems and presentation of a framework to assist managers faced with decision-making in complexity, based on data collected in a survey