SummaryDuring a recent epidemy of influenza, 6 cases of serious pulmonary complications were observed, including one death. As has been previously observed, the severity of the influenza is conditioned by the secondary pneumopathy. The staphylococcal complication is the most severe for it causes serious toxic reactions and very extensive pulmonary changes, which usually respond to antibiotic therapy.The pathologic, clinical and X-ray findings of these pulmonary complications are again described. The factors influencing the incidence of bacterial pulmonary complications in the course of influenza are discussed.