Maternal mortality in Kigoma Region, western Tanzania, was assessed as part of ongoing efforts to reduce maternal deaths in the area. A sisterhood survey was carried out using a questionnaire in which respondents were asked about their sisters who died during pregnancy, childbirth or within six weeks after childbirth. Three thousand and twenty nine individuals were interviewed. The overall estimated maternal mortality ratio (MMR) in Kigoma Region was 606 per 100,000 live births (95% CI 518-695). In urban areas, the MMR was 447 (95% CI 262-635), compared to 638 (95% CI 539-737) in rural areas. The highest NMR of 757 was found in Kigoma rural district, the most isolated part of the region (95% CI 599-916). Although the differences are not statistically significant, they may indicate poor accessibility as a risk factor. Maternal mortality in Kigoma is high when compared to other regions in Tanzania. The sisterhood method is relatively simple and convenient for estimating maternal mortality in resource-poor countries.