This paper describes central and peripheral eustachian tube function in relation to tympanoplasty. Central obstruction of the eustachian tube at the pharyngeal orifice is frequently correctable and is not a contraindication to tympanoplasty, whereas chronic cicatricial peripheral obstruction of the eustachian tube at the isthmus is a contraindication to tympanoplasty. These findings are based on tubal patency pressure studies measured with a mercurial manometer with the patient performing the Valsalva maneuver, with catheterization of the eustachian tube, and with politzerization. If the patient can autoinflate the middle ear and if the eustachian tube will open with politzerization, then the likelihood exists that there is no peripheral obstruction of the eustachian tube and you have a good candidate for tympanoplasty. When there is a perforation of the ear drum, the best test for eustachian tube function is microscopic examination of the middle ear mucosa. If the middle ear mucosa is perfectly normal, then you know that you have good eustachian tube function and can proceed with the tympanoplasty.