Background: Various objective parameters of assessing adenoid size on x-ray have been proposed with no agreement on which is most suitable. In this study, the correlation of two radiographicparameters: adenoidal-nasopharyngeal ratio (ANR) and antroadenoid diameter (AA diameter) to postoperative adenoid volume were compared, with a view to determine which is more accurate. Objectives:To determine and compare the correlations of ANR and AA diameter to postoperative adenoid volume, in order to establish which parameter is more accurate in assessing adenoid size on x-ray. Methods: A cross-sectional analytical study conducted at the Moi Teaching and Referral Hospital, Kenya. 107 patients below fifteen years of age who had adenoid hypertrophy and underwent subsequent adenoidectomy were enrolled.Correlation was calculated using Pearsons correlation,controlling for the number of days between x-ray and surgery, which was a potential confounding factor. Comparison of the two correlation coefficients was carried out using Steigers Z-test. Results: The age of the participants ranged from 11 months to 11 years. The mean ANR was 0.70, mean AA diameter was 3.10mm while the mean postoperative adenoid volume was 2.83mL.Correlation of the ANR to the postoperative adenoid volume was0.661(p<0.001) while that of the AA diameter was -0.222 (p=0.022).Null hypothesis was tested using Steigers Z-test and the difference between the two correlation coefficients found to be significant.The ANR is, therefore, determined to have a stronger correlation to postoperative adenoid volume than the AA diameter. Conclusion: ANR is a better predictor of adenoid volume than the AA diameter.