To determine the prevalence and causes of disabling hearing loss in adults and children in Uganda.Cross-sectional survey of ear disease and hearing impairment.A random cluster sample design of the population from the Masindi district of Uganda following the World Health Organization (WHO) guidelines, using a modified version of the WHO Ear Disease Survey Protocol.The prevalence of disabling hearing impairment using the WHO definitions (excluding 0.5 kHz owing to high background noise levels).In the study, 6041 participants were enrolled and underwent audiometric evaluation and an ear examination. The prevalence of disabling hearing impairment was 11.7% in adults and 10.2% in children. A further 2.3% of children in whom thresholds could not be measured were deemed to have significant hearing loss based on screening questions and/or sound-field stimuli. Correctable causes such as dry perforations, cerumen impaction, and chronic suppurative otitis media resulted in disabling hearing loss in 17% of adult subjects and 41% of children. Preventable hearing loss, such as meningitis and noise-induced hearing loss, was present in a further significant percentage of subjects.Ear disease and hearing impairment were found to be important health problems in the Ugandan population. Preventable ear disease is a major cause of hearing loss in the population. It is hoped that the findings of this study will draw attention to the problem in Uganda and will lead to proper allocation of resources for the prevention and treatment of hearing loss and ear disease.