Introduction "In the past"--said Robert Cooper, one of Europe's pre-eminent diplomats--"it was enough for a nation to look after itself. Today it is no longer sufficient." (1) This is particularly true in the health arena, There is an increasing range of health issues that transcend national boundaries and require action on the global forces that determine the health of people. The broad political, social and economic implications of health issues have brought more diplomats into the health arena and more public health experts into the world of diplomacy. Simple classifications of policy and politics--domestic and foreign, hard and soft, or high and low--no longer apply. (2) Diplomacy is frequently referred to as the art and practice of conducting negotiations. (3) It is usually still understood to mean the conduct of international relations through the intervention of professional diplomats from ministries of foreign affairs with regard to issues of "hard power", initially war and peace, and--as countries compete economically--economics and trade. But in recent years there has also been an increase in the number of international agreements on "soft issues", such as the environment and health; it is now recognized that some of these issues have significant "hard" ramifications on national economies. The term "global health diplomacy" aims to capture these multi-level and multi-actor negotiation processes that shape and manage the global policy environment for health. Global health diplomacy is at the coal-face of global health governance --it is where the compromises are found and the agreements are reached, in multilateral venues, new alliances and in bilateral agreements. It is a world to which outsiders find it difficult to relate, where the art of diplomacy juggles with the science of public health and concrete national interest balances with the abstract collective concern of the larger international community in the face of intensive lobbying and advocacy. No longer do diplomats just talk to other diplomats--they need to interact with the private sector, nongovernmental organizations, scientists, activists and the media, to name but a few, since all these actors are part and parcel of the negotiating process. Global health diplomacy is gaining in importance and its negotiators should be well prepared. Some countries have added a full-time health attache to their diplomatic staff in recognition of the importance and complexity of global health deliberations; others have added diplomats to the staff of international health departments. Their common challenge is to navigate a complex system in which issues in domestic and foreign policy intertwine the lines of power and constantly influence change, and where increasingly rapid decisions and skilful negotiations are required in the face of outbreaks of disease, security threats or other issues. Missions to the United Nations and international organizations--for example, in New York and Geneva--increasingly need to deal with health issues, as do the classical bilateral embassies. An important part of global health diplomacy still takes place within the World Health Organization; indeed it has recently gained new momentum through the negotiation during the past five years of the Framework Convention on Tobacco Control and the International Health Regulations. But the venue of global health diplomacy has shifted to include other spaces of negotiation and influence, and the number of organizations dealing with health has increased exponentially. At all levels we are witnessing a diversification of actors, the most illustrative development being the growth of public--private partnerships and platforms around a multitude of health issues, all clamouring for attention and funds. It is clear that the profound change underway requires new mechanisms and new skills for global health diplomacy. Yet an informal survey by the authors of staff of the international departments of health in countries that belong to the Organisation for Economic Co-operation and Development (OECD), in Latin America and of health attaches in Geneva has confirmed that many do not feel well prepared for the challenges that confront them. …