The Eustachian tube swallow test (ETST) proposed by Williams (1975. Ann. Otol. Rhinol. Laryngol. 84, 339-343) and Bluestone (1975. American Electromedics Corp, New York) was performed on both ears of 62 otologically normal young adult participants in a scuba diving course. The results of the ETST were evaluated according to various pass-fail criteria. A 95% pass rate was achieved only when applying the most lenient criteria, those which considered a minimal shift in either tympanometric peak pressure or amplitude. There was no relation between the subjects' performance on the ETST and the otoscopic evidence of barotrauma after an actual dive. The ETST was of no practical value in screening prospective divers.