We present an analysis of the otological and audio logical findings in 63 patients (113 ears) in which a myringotomy for suspected serous otitis media has been performed. In 98 ears (87 %) the impedance data correlated with otoscopy. Tympanograms did not give further information than otoscopy alone in 49 patients with reliable pure-tone audiometrical results, whereas tympanograms would have missed 6 out of 78 ears containing fluid and 6 out of 49 ears who improved in hearing following myringotomy and transtympanic tube therapy. We feel, however, that, in patients who are too young or too retarded to be tested audiometrically, tympanometry in combination with otoscopy could eventually be helpful in settling the indication for a myringotomy, since 3 out of 83 ears with middle ear fluid and hearing improvement following transtympanic tube therapy had pathological tympanograms in spite of normal-seeming ear drums.