Idiopathic blue eardrum is a term used to designate a chronic condition characterized by dark-blue eardrum. This condition is said to arise from unknown reason as a consequence of nontraumatic bleeding into the middle ear cavities. Although many authors have reported the blue eardrum since it was first thoroughly described 'blue drum membrane' by Shambaugh(1929), the pathogenesis of blue eardrum is still controversial, as it is still undetermined whether it is a variant form of otitis media with effusion or a quite independent clinical entity. In the present study, we analysed 17 cases of idiopathic blue eardrum to evaluate its clinical findings and related pathogenesis. The results suggest that it has a possibility of different clinical entity rather than different phase of otitis media with effusion.