This case-control study was conducted to assess the risk, among children aged 0-12 years, of developing meningitis tuberculosis (MT) associated with a lack of intradermal BCG vaccination. Cases (45) of MT admitted for treatment at the Fundacao Benjamin Guimaraes Hospital (Belo Horizonte, MG, Brazil), from 1975 to 1981, were matched for age at hospitalization, date of hospitalization and nutritional status, with two types of controls--patients with acute diarrhoea (AD) and patients with acute non-tuberculous bacterial pneumonias (BP)--admitted to the same hospital. Vaccination status was ascertained from the patients' medical records. Results showed a risk for MT, estimated by the odds ratio, between BCG non-vaccinated and BCG vaccinated patients, of 6.7 (95% Cl 2.3-19.0) comparing cases and AD controls, of 4.0 (95% Cl 1.5-11.0) comparing cases and BP controls and 5.7 (95% Cl 2.3-14.0) comparing cases with both controls. When adjustments were made for place of residence (Metropolitan Region of Belo Horizonte and other regions of Minas Gerais State), the risks decreased to 5.2 (95% Cl 1.9-14.0) and 2.9 (95% Cl 1.2-7.3) comparing cases with AD and BP controls, respectively.