Bacterial meningitis is a major cause of childhood morbidity and mortality in South Africa. However, comprehensive regional or national epidemiological data, essential for rational public health interventions, are lacking. The purpose of this 1-year prospective study, from 1 August 1991 to 31 July 1992, was to define the magnitude of the problem of childhood bacterial meningitis in Cape Town. The study group consisted of all children, aged > 1 month to < 14 years, who presented with proven bacterial meningitis at all the hospitals in the Cape Town metropolitan area. During the year 201 cases were identified: 101 (50.2%) were due to Neisseria meningitidis, 74 (36.8%) were due to Haemophilus influenzae and 26 (12.9%) were due to Streptococcus pneumoniae. The overall incidence rate (95% confidence interval) for children less than 14 years, 5 years and 1 year was 34 (30-40), 76 (65-88) and 257 (213-309) per 100,000 children, respectively. The rate was highest in black infants, 416 (316-545)/100,000. This was 2 times greater than the rate in coloured infants and about 4.5 times greater than the rate in white infants. The median age of all the children was 10 months. The ages of children with haemophilus and pneumococcal meningitis were similar, 9 and 7.5 months respectively (P = 0.43), while children with meningococcal meningitis were significantly older (22 months) than the others (P < 0.01). The overall case fatality rate was 5%, and 12.9% of survivors had significant neurological sequelae (disability) on discharge.