Introduction. Adenoid hypertrophy (AH) is a common childhood disorder. Adenoid plays a significant role in the pathogenesis of otitis media with effusion (OME). The aim of this study is to critically appraise the tympanometric finding among children with adenoid hypertrophy in Port Harcourt, Nigeria. Methodology. A Prospective, controlled study carried out among newly diagnosed cases of adenoid hypertrophy at the ENT clinic of the UPTH, between November 2014 and June 2015. Tympanometry was done on each child and each ear was considerably studied as a single entity. Types B and C tympanograms were used as indicators of OME. Data was collected and analyzed using SPSS version 20. Results. Sixty-eight cases of adenoid hypertrophy were seen within the study period and 136 ears were studied. Forty (29.4%) ears had type B tympanogram, while 36 (26.5%) ears had type C. The incidence of OME was 55.9%; there were 12 (17.6%) unilateral OME, while bilateral OME was 32 (47.1%). Grade 3 AH was prevalent and was statistically significant with the OME. Conclusion. This study had shown adenoidal hypertrophy as a significant risk factor for OME in children. There was more bilateral OME than unilateral. The more severe grade of AH was more prevalent and it was shown to be statistically significant with OME, thus being a significant risk factor for OME in children. This establishes the need for prompt hearing evaluation and management.