Flu vaccinations are administered worldwide every winter for prevention. We herein describe a case of acute lung injury resulting from a pathologically confirmed alveolar hemorrhage, which may have been closely related to a preceding vaccination for pandemic influenza A of 2009/10. The present patient had been hospitalized with an acute lung injury after flu vaccination one year prior to the present hospitalization, however, he received another flu vaccination. We should consider a vaccine-related adverse reaction as a potential cause of pulmonary disease if patients present with this illness during the winter season.