The majority of influenza cases are not associated with complications. Secondary bacterial pneumonia, commonly caused by Streptococcus pneumoniae or Staphylococcus aureus, is well known to most clinicians. Primary influenza viral pneumonia, characterized by rapidly progressive hypoxia and respiratory insufficiency together with non-consolidating pulmonary infiltrates, has a high mortality rate. In 3 patients, a man aged 74 years, and two neonates aged 11 months and 4 weeks respectively, primary influenza A pneumonia was diagnosed. In the latter two patients the virus was cultivated from sputum. Despite intensive supporting and drug treatment, the first and the last patients died. In view of evolving therapeutic possibilities, notably regarding neuraminidase inhibitors, it is important that clinicians recognize this complication of influenza at an early stage.