In pregnant women, the reported cases of hemoptysis were most often mild and had an identified cause. Between November 2003 and January 2006, three pregnant women at 16-20 weeks gestation were admitted to our respiratory intensive care unit for massive hemoptysis. One of the women had experienced mild hemoptysis, considered as idiopathic, during her first pregnancy, with no recurrence until her second pregnancy. In all three cases, hemoptysis was massive. CT scan after iodine injection did not reveal any cause. Opacification of the bronchial artery showed hyperemia from abnormally dilated and tortuous bronchial arteries. Bronchial artery embolization (BAE) was performed in all three patients, successfully in two. Intravenous vasopressin was used as second-line treatment for recurrent bleeding after BAE in one patient. The women carried the pregnancy to term with delivery of healthy infants. Further complete investigation after the births did not identify any possible local (pulmonary) or general cause of bleeding in these three patients. Although these cases could be considered idiopathic, the close association with duration of pregnancy suggests the hemoptysis may be related to hormonal changes.