This study presents measurements of the cross-sectional luminal area of the eustachian tube. Comparisons are made between the lumens of eustachian tubes obtained from temporal bones presenting acute or secretory otitis media and those from noninflamed temporal bones. The material consisted of 71 temporal bones obtained postmortem from individuals up to 2 years of age. Forty-six of these showed no middle ear inflammation, while 25 presented either acute or secretory otitis media. In both groups the lumens of all the eustachian tubes were patent, presenting no obstruction. The mean cross-sectional area of the lumens of inflamed temporal bones was smaller than that of the noninflamed ones. This difference was not found to be statistically significant in the cartilaginous regions and was found to be statistically significant or borderline significant in the bony parts of the eustachian tube.