In two of its regular sessions, the Royal Academy for Medicine of Belgium consulted with influenza experts on the current threat of a severe pandemic outbreak, and in particular on the eventuality that this outbreak may be caused by a virus identical or related to the avian influenza virus H5N1. On the basis of this consultation, the Academy issued an advisory statement to the Belgian federal and Flemish regional Health Authorities. The Academy shares the experts' concern that the forthcoming influenza pandemic may well affect a larger part of the population than previous pandemics in 1958, 1968 and 1977. The Academy found it satisfying that the Belgian government is developing an appropriate pandemic containment plan. A primary objective of the plan is to safeguard general health care during the pandemic. Availability of staff and infrastructure and continuity of medical supplies must by all means remain intact. Therefore, employees in these sectors are an important target group of preparatory actions, in particular briefing about, and field rehearsals of the containment plan. Health care workers, elderly people and the chronically ill constitute a priority group eligible for vaccination with the antigens of the pandemic virus and for the administration of virus inhibitors. The effectiveness of antiviral treatment and prophylaxis during a pandemic is, given the lack of experience, uncertain. The fact that such remedies will be available must not create a false sense of security and must certainly not lead to reduced alertness with regard to the preparation and implementation of other measures. Panic reactions among the population must be avoided. Therefore, the population must be informed in due course about appropriate ways of conduct when a pandemic strikes, e.g. recognition of the early signs of influenza, the need to consult a general practitioner at once, the reason why being nursed at home is to be preferred to being hospitalized, etc. Indifference towards vaccination must be overcome. In the period prior to the pandemic people must be encouraged to obtain vaccination against the prevalent interpandemic virus strains. Belgium does not stand alone in the avian influenza threat and can largely benefit from participating in the current international initiatives to co-ordinate measures.