Idiopathic hemotympanum or idiopathic blue ear drum that contains a mucous brownish or hemorrhagic secretion in the middle ear is a chronic condition in which the entire drum is of a distinct blue colour and in which etiologic factors such as cranial injury, bleeding from nasopharynx, operative injury, barotrauma, tumours, hemorrhagic diathesis and anomalies have been ruled out. The pathogenesis of the ididopathic hemotympanum is still controversial, as it is still undetermined whether it is an varient of otitis media with effusion of a quite independent clinical entity. Recently we experienced four cases of idiopathic hemotympanum which were treated with simple mastoidectomy and ventilation tube insertion.