The present study describes the audiological profile of genetic hearing loss resulting from GJB2 mutations in northern Greece, as this represents the most frequent single cause of childhood sensorineural hearing loss. The 35delG mutation in homozygosity was detected in 27 of 107 patients (25.2%). The audiological profile is that of a profound or severe sensorineural hearing loss, with a sloping or flat configuration of the audiogram, mostly symmetrical, non-progressive and affecting more the higher frequencies. This profile underlines the importance of early identification and genetic family counseling leading to the future possibility of prevention of deafness.