ObjectiveTo study the results of petrosal bone imaging and audiometric long-term follow-up of two patients with branchio-oto-renal (BOR) syndrome and relate them to the clinical features, including caloric responses.Study DesignLongitudinal case study.SettingTertiary referral center.PatientsA father and son with the BOR syndrome.Main Outcome MeasuresBoth patients underwent imaging studies to detect and evaluate inner ear anomalies. Longitudinal audiometric analysis of the hearing threshold data over the previous 23 years was performed. Caloric tests were performed at various ages.ResultsThe son had a short, wide internal acoustic canal, a hypoplastic cochlea, a plump vestibule, and a wide vestibular aqueduct on both sides; the semicircular canals and endolymphatic sac were of normal size. He showed progressive fluctuant sensorineural hearing loss. Caloric tests disclosed hyporeflexia on the left side. The father had a plump internal acoustic canal and hypoplastic cochlea on both sides. The left vestibule was hypoplastic, and the left vestibular aqueduct was marginally enlarged. He showed severe hearing impairment, without substantial progression or fluctuation, and caloric areflexia on the left side.ConclusionThese findings suggest a correlation between progressive fluctuant sensorineural hearing loss with caloric hypofunction and the presence of an enlarged vestibular aqueduct in the BOR syndrome. Additional longitudinal case studies are needed to further evaluate such a correlation.