The question of the "brain drain" of health professionals has re-emerged since last exposed in 1970s. This paper is based on exploratory studies in Ghana, South Africa and the UK, a literature review and subsequent tracking of contemporary events. It reviews what is currently known about professional migration in the health sector and its impact on health services in poorer countries. The relevant responsibilities at the global level and source and recipient country levels are then reviewed. It is concluded that that the situation is more complex than portrayed by some of the rhetoric and that meaningful dialogue and consideration of responsibilities is needed. In addition, better information is needed to monitor migration flows; source countries need to improve staff attraction and retention strategies; and recipient countries need to ensure that they do not become a permanent drain on health professionals from the developing countries.