Eustachian tube (ET) function was evaluated in a group of 47 children with tympanostomy tubes who had previously documented persistent otitis media with effusion (OME). Tubal function was assessed using the inflation-deflation and forced-response tests. The study children were between the ages of 2 and 11 years. The passive ET function parameters of these children were within the limits of normal children with negative otologic histories. However, their active tubal function was radically different than normal children; none of them could equilibrate negative pressure, and only four could equilibrate positive pressure. During the forced-response test, further dilation of the ET lumen by swallowing was observed in only five of these 47 children. The findings of the present study suggest that this observed tubal dysfunction is secondary to a defect in the active function.