In this paper, we will try to answer the question: "What are the different factors of rural poverty in Madagascar? To do this, two hypotheses will be discussed: first, the low rate of access to drinking water amplifies the poverty situation. Secondly, limited access to the use of sanitation facilities is one of the determinants of rural poverty. We have drawn statistical and theoretical data from different sources. For the theoretical part, we searched on the internet. In addition, we consulted various reports at INSTAT. It is from these data that we proceeded to the elaboration of this work. In the empirical part, the analysis of the two hypotheses was based on the 22 regions of Madagascar and the environments of residence. This allows us to see the causal relationship between the rate of access to improved water and sanitation infrastructure and the level of poverty. The analyses are always done according to the 22 regions and the area of residence to see the differences.