BACKGROUND Although some authors have suggested that there is some seasonal periodicity in hemoptysis, temporal patterns of hemoptysis have been poorly investigated. The aim of this study is to describe the temporal pattern of severe hemoptysis which required bronchial artery embolization (BAE). METHODS All consecutive patients with at least one episode of hemoptysis which required BAE during a 13-year period were included. Recurring hemoptysis requiring BAE in a patient with previous embolization was included as a new hemoptysis event, unless it occurred within one month from the prior event. Lineal regression was applied to compute the tendency of occurrence of cases along 13 years of record data. The daily and monthly distributions of embolizations were used to study the weekly and monthly seasonal indexes. RESULTS Hemoptysis requiring BAE occurred with some monthly variation demonstrated with two monthly peaks, with the first one occurring during April and the second one during November. CONCLUSIONS Hemoptysis occurred with two monthly peaks. This seasonal trend might be due to different prevalence of respiratory tract infections or to some weather variables. Identification of significant environmental factors could be useful to improve preventive measures.