Objective: Adenoid hypertrophy is a disease whose most serious effect is the obstruction of the nasopharyngeal airway, leading to severe dentoskeletal deformities. The aim of this study was to determine the volume of the nasopharynx in patients with different grades of adenoid hypertrophy. Materials and methods: A retrospective study was conducted. One hundred and twenty-five cone beam computed tomographies of 8 to 12-year-old pediatric patients, obtained from the 2014-2017 database of the School of Dentistry of Universidad de San Martin de Porres, were selected. Romexis 3.6.0 software (PlanMeca®, Finland) was used. In order to make a diagnosis and determine the grade of hypertrophy (Grade 1= healthy, Grade 2= mild, Grade 3= moderate and Grade 4= severe) quantitative and qualitative methods were used; grades 2, 3 and 4 were considered pathological. The same software was used to determine the volume of the nasopharynx. Results: Grade 1 hypertrophy was 44%, mild 36,8%, moderate 13,6% and severe 5,6%, accounting for a pathological adenoid hypertrophy prevalence of 56%. The mean volume of the nasopharynx was 4.985, 3.375, 2.154 and 0.944cm3 for grades 1, 2, 3 and 4, respectively. Conclusions: There is a high prevalence of pathological adenoid hypertrophy (56%). The volume of the nasopharynx decreases according to the severity of the adenoid hypertrophy.