PURPOSE: To find the rebleeding factors in bronchial arterial embolization for treatment of hemoptysis, a retrospective study was performed. MATERIALS AND METHODS:Medical records, anglographic findings and embolic materials of 35 patients who had undertaken arterial embolization for control of hemoptysis were reviewed. The period of follow-up for rebleeding was from 3 to 32 months after arterial embolization. We investigated the anglographic findings of extravasation, neovascularity, intervascular shunt, aneurysm and periarterial diffusion. Neovascularity was classified as mild(numerable neovascularity) and severe(innumerable). RESULTS: Rebleeding occured in 15(43%) among 35 cases. Only two of 11 cases with no past episode of hemoptysis showed recurrence, while 9 of 15 cases who had more than three episodes did. Severe neovascularity were seen in 11 of 15 recurred cases, but seven of 20 non-recurred cases showed severe neovascularity. More than three anglographic findings representing hemoptysis were seen on 11(73%) among recurred 15 cases and seven(35%) among non-recurred 20 cases. The lesion was supplied by more than two different arteries on 8(54%) of the recurred cases, but only three(15%) of the non-recurred cases. Six of seven cases persistent neovascularity after arterial embolization were recurred. CONCLUSION: The history of repeated hemoptysis, severe neovascularity, variable anglographic findings, and post-embolization persistency of neovascularity were the factors related with the rebleeding after arterial embolization for hemoptysis. Careful and active arterial embolization are required on these conditions.