in the success of tympanoplasty operations. The study was designed prospectively to reveal the role of Xe-133 ventilation scintigraphy in the determination of eustachian tube (ET) function. Materials and Methods: Thirteen patients who underwent successful tympanoplasty with intact graft and 5 healthy volunteers were included in this study. Xe-133 insufflation into nasopharynx was done using a polyethylene 7F catheter and the patient was asked to perform valsalva maneuver followed by swallowing. Time-activity curves were generated from the region of interest (ROI) corresponding to middle ears; uptake ratio and clearance half-time of xenon 133 were also calculated in this region. Results: Decreased tracer uptake was demonstrated in the ears with tympanoplasty. Mean uptake value was 53.73 +/- 15.73 in volunteers, 46.73 +/- 15.28 in normal ears of operated patients and 39.99 +/- 17.47 in operated ears. There was significant difference of uptake between the normal ears and ears with tympanoplasty (P < 0.0.5). However, there was no significant difference in the washout rate between normals and patients with tympanoplasty. Conclusions: Xe-133 ventilation scintigraphy is a reliable method that gives objective and quantitative information about eustachian tube function. In the early postoperative period the uptake is less than normals.