The amplitude and frequency spectra of otoacoustic emissions are influenced by the condition of the middle ear. These are noninvasive measurements of cochlear function that are accurate, rapid, and simple to perform. In this study, prognostic value of otoacoustic emissions in children with middle ear effusion (MEE) was investigated. A total of 49 children aged 3.5 to 11.2 years with MEE were included. Spontaneous otoacoustic emission, transient evoked otoacoustic emission (TEOAE), and distortion product (DP) otoacoustic emission measurements were performed on each ear before medical treatment and were compared according to the responsiveness of medical treatment (medicine responder vs medicine nonresponder groups). Responses of spontaneous otoacoustic emissions and DP audiogram showed no significant difference between the 2 groups but TEOAE response was significantly decreased in medicine nonresponders (P < 0.05). Positive responses of the DP Input-Output function curve in geometric mean frequencies at 5 and 6 kHz using a primary tone of 55 dB SPL were significantly detected in medicine responders (P < 0.01). The sensitivity, specificity, and predictive values of TEOAE and the DP I-O function curve in geometric mean frequency at 6 kHz using a primary tone of 55 dB SPL showed the high prognostic value of these tests in terms of predicting response to medical treatment in the patients with MEE. This suggests that otologists may have to be more aggressive in their treatment of children with MEE who showed no response.