The paucity of up-to-date and representative epidemiological data on hearing disorders in Nigeria has been observed as undermining the effective advocacy of prevention initiatives. This study attempts to address this problem by evaluating the prevalence and pattern of hearing impairment in school entrants. Parental interviews, otoscopy, pure-tone audiometric screening (frequency 0.5-4 kHz) and tympanometric examinations were conducted for a representative sample of 359 school children in an inner city area of Lagos. The prevalence of hearing loss was 13.9%. Middle ear abnormalities were noted in 20.9% of the study population, of which 18.7% were reported with otitis media with effusion. Impacted cerumen, documented in 189 children (52.6%), was the most common disorder. It showed significant association with hearing loss (P<0.001) and school performance (P<0.01). Tympanic membrane abnormalities were observed in 144 (40.1%) children. Of these, 45 (31.3%) showed abnormal tympanograms while 28 (19.4%) reported hearing loss (P<0.05). The early detection and management of hearing problems is relatively rare, thus precluding the determination of possible aetiological factors for the observed abnormalities. Poor public awareness, dearth of relevant facilities and the lack of early screening programmes are major known contributory factors. The well established national immunisation programme offers a cost-effective platform within the primary health-care system for addressing the high prevalence of hearing abnormalities in school children.