An outbreak of meningitis with 85 secondary cases and an unusually high attack rate of 16% occurred in a rural village in southern Tanzania. We investigated risk factors for clinical illness in a community-based case-control study. Attending a commercial mobile video show carried an age- and sex-adjusted odds ratio of 8.0 (95% confidence interval: 3.8-16.8). The videos had been shown in a windowless and overcrowded storeroom and had been attended by the primary case, a visitor from neighbouring Mozambique who died from meningitis on the following day. We conclude that mobile video shows, which have become popular in many developing countries, constitute a potential health hazard in areas prone to meningitis epidemics.