The influence of endonasal operations on tube dysfunction was examined. Because of rhinomanometric proved reduced ventilation a nasal septal reconstruction, in some patients combined with turbinotomy, was performed. Before the operation and then up to two years after the operation tube function was registrated using tube manometry. Compared with the praeoperative results 12 patients out of 37 showed an improvement in tube function. After the operation 7 out of 28 patients were able to provide active equalization of a negative pressure in the middle ear and thus required the ability for physiological middle ear ventilation. In some cases the optimal tube manometric results were achieved not before the end of the observation period of two years. This investigation leads to the conclusion that in cases of reduced ventilation a nasal septum reconstruction should precede a tympanoplasty in order to improve tube function. An improvement of tube function only by permanent ventilation over a period of 2 years can not be obtained, as could be proved by statistic analysis.