Background: Adenoid hypertrophy is one of the most common health problems affecting the pediatric population. This study aims to correlate the adenoidal–nasopharyngeal ratio (ANR) with otitis media with effusion (OME). If OME is left undiagnosed it can lead to long-term consequences like hearing impairment, learning and speech disabilities, and even chronic otitis media in children. The current study was a cross-sectional study conducted at a tertiary care center in Haryana, India. ANR was determined by dividing adenoidal depth with nasopharyngeal depth on the plain lateral radiographs and OME was diagnosed by tympanometry. Results: The study consists of 70 children in the age group of 3–12 years with symptoms of adenoid hypertrophy. The children were almost similar in number in the three age groups we had selected with male preponderance. Otoscopy and tympanogram results were matching in our study. Types B and C tympanograms indicate middle-ear effusion seen in either one ear or both. In our study, type-A curves (non-diseased) were well correlated with low ANR, and types B and C curves (diseased) were well correlated with high ANR. Conclusion: Adenoidal–nasopharyngeal ratio obtained from the X-ray will give an arithmetic measurement of adenoid mass with respect to available nasopharyngeal space. The simple outpatient tympanometry provides objective evidence of OME. The present study proved the positive correlation between ANR and OME by correlating ANR with tympanogram findings.