Commissural lip pits, pinna dysplasia, pre-auricular sinus and hearing loss constitute a recently described autosomal dominant branchial arch syndrome. In a large family, eight out of the 74 members were also affected by conductive hearing loss. No inner ear abnormalities could be demonstrated on the CT scans. In three patients (four ears) out of four patients (six ears), exploratory tympanotomy revealed serious ossicular chain anomalies. In one ear, round window aplasia was also present. Long-term hearing improvement could only be achieved in one ear.