Acute otitis media and otitis media with effusion (OME) have often been observed in children with bacterial meningitis. OME has also been proposed as the mechanism of reversible hearing loss after meningitis. In this controlled study, children with acute bacterial meningitis were studied using auditory brainstem responses (ABR), otoacoustic emissions, tympanometry and otoscopy. An age- and sex-matched control was recruited for each patient and the incidence of acute otitis media and OME was compared between the two groups. One hundred and twenty-four children with meningitis were studied. Ninety-two children (74 per cent) had meningococcal meningitis. Five patients (4 per cent) had conductive hearing loss (ABR threshold > or = 30 dB HL) at the time of discharge from hospital. None of the patients or controls had acute otitis media. Patients and controls were well matched for risk factors for OME and the prevalence of middle ear effusion in patients and controls was 7.2 per cent and 11.3 per cent respectively. The relative risk of OME in the children with meningitis was 0.64 (95 per cent confidence interval 0.29 to 1.42). After nine months, three of the five children with meningitis and conductive hearing loss had regained normal hearing. In contrast to previous reports, there was no relationship between bacterial meningitis and acute otitis media or OME in this study. Nevertheless, coincidental conductive hearing defects were identified as the cause of reversible hearing loss in three patients.