A better understanding of hearing disability situation would advance hearing health care in the developing world. Vietnam is a developing country with audiology at its early stage of development. This study examined the situation (degree, types and causes) of hearing impairment, the effects of age and gender on hearing impairment, and the age of identification and its relationship with degree of hearing impairment in Vietnamese children. Sixty nine participants aged from 20 to 129 months with prelingual-onset hearing loss were assessed during Global Foundation For Children With Hearing Loss humanitarian field missions. Data on hearing assessment findings, including case history and pure-tone audiometric outcomes, were analyzed. Results showed that hearing impairment of participants ranged from moderate to profound levels, and that sensorineural pathologies accounted for 80% of hearing loss. Maternal rubella was the most common cause. Age and gender showed no statistically significant associations with degree of hearing impairment. Average age of identification was 23.2 months and a greater proportion of children with profound hearing loss than those with milder degrees were noted. To reduce the prevalence of childhood hearing loss, improved immunization programs against infectious diseases and development of universal newborn hearing screening programs are highly recommended.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science