Over the past 30 years maternal mortality estimates for Papua New Guinea have varied widely. There is no mandatory vital registration in PNG, and 85% of the population live in rural areas with limited or no access to health services. Demographic Health Survey data for PNG estimates the maternal mortality ratio to be 370 deaths per 100,000 live births in 1996 and 733 in 2006, whereas estimates based upon mathematical models (as calculated by international bodies) gave figures of 930 for 1980 and 230 for 2010. This disparity has been a source of considerable confusion for health workers, policy makers and development partners. In this study, we compared 2009 facility-based survey data with figures from the national Health Information System records. The comparison revealed similar maternal mortality ratios: for provincial hospitals (245 and 295), government health centres (574 and 386), church agency health centres (624 and 624), and nationally (394 and 438). Synthesizing these estimates for supervised births in facilities and data on unsupervised births from a community-based survey in one province indicates a national MMR of about 500. Knowing the maternal mortality ratio is a necessary starting point for working out how to reduce it.