This paper presents a family pedigree of sensorineural hearing loss in patients with a mitochondrial DNA (mtDNA) deletion. Genomic DNA screenings including myo 15 and connexin 26 were normal. MtDNA deletions are associated with many pathophysiologic conditions, including neurological disorders, sensorineural hearing loss, ischemia, cardiomyopathies and aging. Several mitochondrial disorders secondary to mutations or deletions in mtDNA have been identified in association with deafness. The present study describes a pedigree of five individuals with hearing loss who harbor a 4977 bp common aging deletion, in their mtDNA. Chromosomal analysis was normal in all affected individuals. Audiologic and molecular biologic findings of these patients suggest that the common aging deletion of mtDNA may be a predisposing factor in sensorineural hearing loss in this family.