This volume presents articles which focus on the ethical evaluation of performance-enhancing technologies in sport. The collection considers whether drug doping should be banned; the rationale of not banning ethically contested innovations such as hypoxic chambers; and the implications of the prospects of human genetic engineering for the notion of sport as a development of ’natural’ talent towards human excellence. The essays demonstrate the significance of the principles of preventing harm, ensuring fairness and preserving meaning to appraise whether a particular performance enhancer is acceptable in the context of sport. Selected essays on various forms of human enhancement outside of sport that highlight other principles and concepts are included for comparative purpose. Sport enhancement provides a useful starting point to work through the ethics of enhancement in other human practices and endeavors, and sport enhancement ethics should track broader bioethical debates on human enhancement. As a whole, the volume points to the need to consider the values and meanings that people seek in a given sphere of human activity and their associated principles to arrive at a morally grounded and reasonable approach to enhancement ethics.