An investigation was carried out among the military personnel in the Self Defense Forces to assess acoustic trauma in association with the onset of endolymphatic hydrops (ELH). Four hundred seventy servicemen were offered general physical examinations in an inpatient setting prior to their discharge from the SDF for mandatory age retirement. A questionnaire on the history of intense acoustic exposure and of dizzy spells was given to the same individuals. A routine ENT examination and audiography were performed for each of them. The following results were noteworthy: five men had a history of Ménière's disease, and 32.5 percent of those questioned had experienced dizzy spells. Hearing thresholds in those who reported that they had had dizzy spells were considerably higher than those who had not had such spells. Although a quantitative analysis as well as a well-established control study seems necessary to implicate acoustic trauma as one of the etiological factors of ELH, this study strongly suggests a relationship between acoustic trauma and development of ELH among the SDF personnel examined.