OBJECTIVE To document the impact of tuberculosis and HIV-1 on maternal mortality. METHODS Prospective study, 1997 and 1998; retrospective analysis, 1996. METHODS Known maternal deaths, defined as the death of a mother within a year post-delivery, were studied in Durban, KwaZulu Natal. The HIV-1 status, presence of tuberculosis, maternal clinical features and perinatal outcomes were documented. The overall as well as HIV-1 and tuberculosis-specific maternal mortality rates for the hospital were calculated. The attributable fraction of deaths as a result of HIV-1 was calculated in the overall group and in those with tuberculosis co-infection. RESULTS A total of 50 518 deliveries and 101 maternal deaths were recorded. Of the deaths, 29.7% (30/101) were HIV-1 infected. The overall mortality rate was 200/100 000; for HIV-1-infected women this was 323.3/100 000, HIV-1-negative mothers, 148.6/100 000 live births. The attributable fraction of overall deaths as a result of HIV-1 was 15.9% Fourteen of the 15 mothers with tuberculosis were HIV-1 co-infected. The mortality rate for tuberculosis and HIV-1 co-infection was 121.7/1000; for tuberculosis without HIV-1 co-infection, 38.5/1000. Fifty-four per cent of maternal deaths caused by tuberculosis were attributable to HIV-1 infection. Thirty-five per cent of maternal deaths were associated with stillbirths; perinatal outcomes were no different between groups of mothers with tuberculosis, HIV-1 or neither infection. CONCLUSIONS Tuberculosis and HIV-1 are emerging as significant contributors to maternal mortality in KwaZulu Natal. Any attempt to improve maternal health must also include careful screening and investigation for tuberculosis in high-risk pregnant women.