Introduction: Hearing loss was found to be the most common sensory disorder in children. The prevalence of congenital hearing loss was found to be one in one thousand of live births. Fifty percent of the cause is genetic and the autosomal recessive nonsyndromic sensorineural hearing loss is responsible for 80% of the genetic causes. Aim of the work: The aim of this work was to study the genetic causes of ARNSNHL, mainly mutation in the gene encoding connexin26 (Cx26), and to correlate the identified gene and mutation with the degree and configuration of the hearing loss, the progressiveness of hearing loss, as well as its relation to language development. Subjects and methods: One hundred children were collected from different clinics in Kuwait, their age ranged from 6 months up to eighteen years and those who showed congenital ARNSNHL were chosen. The study started in September 2005 and ended by November 2007. A questionnaire was given to the parents. Otoscopic examination, PTA to identify the hearing threshold level in children > 5 years old, while for children < 5 years old behavioral test was done using free field test, imittancemetry examination (tympanogram and acoustic reflex threshold), ABR test and TEOAE tests, CT scan study was performed. In addition, genetic tests to detect Cx26 mutations using polymerase chain reaction and primers, as well as sequencing using different primers was undertaken, statistical analysis was then performed. Results: Out of the total 100 cases, 15 children showed to have positive results for Cx26, 9 of them were heterozygous and 6 of them were homozygous. Twelve subjects (eighty percent) of the Cx26 cases were due to 35delG. Out of the 9 heterozygous, 6 of them showed positive results for D1 (35delG), while 3 children were found to have positive results for D2 (G2A at location base 71). All the 6 homozygous cases showed to be positive for D1 (35delG). Thus, the results showed that 80% of the positive genetic results cases had 35delG. Fifty seven percent of the cases had positive family history of hearing loss, while the sporadic cases were 43%. All cases had bilateral SNHL; 62% had a history of rapidly progressive hearing loss, while 38% showed slowly progressive SNHL. Seventy percent of the study group was prelingual and 30% were postlingual. The heterozygous children showed different degrees of hearing loss, ranging from mild to profound, 6 of them were postlingual, while 3 were prelingual, 7 children had positive family history of hearing loss and only 2 were sporadic, 5 of them showed slowly progressive type of hearing loss and 4 had rapidly progressive type of hearing loss. On the other hand, all the homozygous children had severe to profound SNHL; all of them were prelingual; all had positive family history of hearing loss and all of them were showing the rapidly progressive type of SNHL. Conclusion: We concluded from our work, that 80% of the cause of ARNSNHL in Kuwaiti population was 35delG mutation and 20% was due to G2A at location base 71. Fifty seven percent of the cases showed positive family history of hearing loss. The homozygous cases presented with more severe clinical pictures compared to the heterozygous cases. Recommendations: Neonatal hearing screening programs and screening programs for school children to detect delayed congenital SNHL is recommended. Follow up programs for children at risk and genetic testing for other mutations is also mandatory.