AbstractConclusion: It is recommended to perform follow-up tympanometry and if necessary tonal audiometry in children who have normal plain otoscopy findings after recovering from acute otitis media (AOM). Children with Type B tympanogram, 3 months following the onset of AOM, are very likely to have a conductive hearing loss. Type B tympanogram is a much better indicator of effusion in the middle ear compared to plain otoscopy. Objective: This study was undertaken to investigate the frequency and duration of middle ear effusion in children following an episode of acute otitis media, to track changes in tonal audiometry and tympanometry findings in the post-AOM period, and recognize the optimal timing for performing both tests. Methods: In this study, 125 children aged 5-7 years with bilateral AOM were randomly selected and separately followed up for 3 months. The children underwent six ear, nose, and throat (ENT 1-6) examinations, six tympanometries (TM 1-6), and three tonal audiometries (TA 1-3). Evaluation of nasopharynx was done at the ENT 1 examination. Children who received ventilation tubes were followed for 21 month altogether. Results: At the first otoscopy, pathological findings were recorded in 250 ears/125 children (100.0%). The number of pathological otoscopy findings decreased at each subsequent examination. At ENT 6 all children had normal otoscopy findings. Type B tympanogram was detected in 49/250 (19.6%) ears at TM 6, performed 3 months following the onset of the disease. At the TA 1 conductive hearing impairment was recorded in 158/250 (63.2%) ears, at TA 2 in 66/250 (26.4%), and at TA 3 in 39/250 (15.6%). Most of them were associated with Type B tympanogram.