Catamenial hemoptysis is a tenn used to describe recurrent hemoptysis occuring at the time of menstruation and is caused by the presence of thoracic endometriosis. The diagnosis is almost always established on the clinical grounds and by exclusion of other causes of recurrent hemoptysis. The pathogenesis of the thoracic endometriosis is not clear but several hypothesis have been proposed, such as retrograde flow of the endometrial tissue through the diaphragmatic defects, microembolization through pelvic veins and differenciation into endometrial tissues. We report a case of a 35-year-old woman who presented with catamenial hemoptysis caused by the endometriosis of lung parenchyme. The lesion was localized to the right upper lobe posterior segment and right lower lobe superior segment by the computerized tomogram of the chest during the lime of mensturation and treated effectively with bisegmental wedge resection.