Despite the reduction in incidence of acute suppurative otitis media since the introduction of antibiotics, the incidence of chronic middle ear effusion and chronic otitis media have not experienced a similar reduction. Eustachian tube dysfunction is believed to be a principal etiological factor in these cases. The inflation-deflation technique to measure tubal function has shown promise in a number of laboratories, and is the basis for our present studies. Traditional application of this technique has been to document the capability of patients with chronic otitis media to equilibrate an induced positive or negative pressure. These patients are compared to a control group of patients with recent traumatic perforation, negative otologic histories, and normal tympanograms in the uninvolved ear. We have applied this test to observe its relationship to successful take of a tympanic membrane graft. The overall pattern of our results suggests that the capability to reduce an induced negative pressure is most frequently associated with successful tympanic membrane closure. However, compromise or even total failure to reduce an induced negative pressure does not preclude successful grafting of the tympanic membrane; nor should such failure to reduce negative pressure by this technique serve as a contraindication to surgery. Our results do suggest that during induced positive pressure application, spontaneous opening of the eustachian tube at opening pressures below +150 mm H2O may be discriminatory between success and failure.