The Dutch Ministry of Health asked the Health Council for advice on how to prepare for a possible influenza pandemic. In two advisory reports the Committee responsible indicated the measures that it believes would need to be taken if such a pandemic were to reach the Netherlands. During a pandemic, the Committee recommends that every resident of the Netherlands with influenza-like illness should be treated with neuraminidase inhibitors such as antiviral agents. This approach serves to mitigate the course of the disease, to reduce infectivity and to allow patients to build up immunity to the virus. Since up to 30% of the population could become ill, the Committee anticipates that a stock of five million courses of the neuraminidase inhibitor oseltamivir is sufficient. If a pandemic were to occur at a time that the stock does not exceed the present 225,000 courses, the committee advises restricting treatment to three specified groups of patients. If the first few patients are traced shortly after they fall ill, the Committee recommends treatment of the patient and postexposure prophylaxis for his/her close contacts. The Committee does not advocate prophylaxis in general, but it can envisage prophylaxis for particular groups of patients or under particular circumstances. The Committee believes that in order to reduce rapid spread of the virus, schools should be closed and events where large numbers of people gather in a confined space should be cancelled. Because this recommendation would have major social and economic consequences, the Committee understands that its implication will depend on the anticipated severity and extent of the pandemic. The Committee regards vaccination against influenza as the best means of protecting the population. The development of a vaccine should be the absolute priority.