Power is an inescapable aspect of all social relationships, and inherently is neither good nor evil. Doctors need power to fulfil their professional obligations to multiple constituencies including patients, the community and themselves. Patients need power to formulate their values, articulate and achieve health needs, and fulfil their responsibilities. However, both parties can use or misuse power. The ethical effectiveness of a health system is maximised by empowering doctors and patients to develop 'adult-adult' rather than 'adult-child' relationships that respect and enable autonomy, accountability, fidelity and humanity. Even in adult-adult relationships, conflicts and complexities arise. Lack of concordance between doctors and patients can encourage paternalism but may be best resolved through negotiated care. A further area of conflict involves the 'double agency' of doctors for both patients and the community. Empowerment of all players is not always possible but is most likely where each party considers and acknowledges power issues.