This observational study assessed the knowledge of pregnant women attending antenatal clinics at two selected hospitals in Abeokuta South, Nigeria on the causes and risk factors of maternal mortality, identifi ed barriers to knowledge acquisition, and examined the infl uence of parity of respondents on their knowledge of factors causing maternal mortality. Maternal mortality is extremely high in Nigeria, it is defi ned as the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes. Descriptive research design was used in this study and qualitative data from 136 respondents selected randomly, were obtained through a self-designed questionnaire that comprised three sections. Data were analyzed and indicated that parity of the pregnant women do not have an infl uence on their knowledge of factors responsible for maternal mortality. Findings revealed that majority (67.6%) of the respondents had high knowledge on the causes of maternal mortality-haemorrhage, sepsis, prolonged/obstructed labour, anaemia, unsafe abortion, infection, hypertensive disorders, care rendered by unskilled medical practitioners and its risk factors-parity, poverty, place of last delivery and low attendance at antenatal clinic. Educational background, marital status, irregular antenatal visits, socio-cultural practices and occupational status were identifi ed as barriers to knowledge acquisition. This paper concluded that pregnant women may have a high knowledge about the factors responsible for maternal mortality. This is probably due to the fact that all respondents had formal education and because they were interviewed on antenatal clinic days, which suggests that they might have heard about the causes and risk factors for maternal mortality during their visits. Authors recommended that government should employ qualifi ed health professionals and provide medical subsidy, it is hoped that this will ensure that pregnant women get quality care throughout the period of pregnancy and delivery.