The municipalities of Baixada Fluminense, region of the state of Rio de Janeiro, have areas that combine environmental vulnerability and social vulnerability, forming areas of socio-environmental vulnerability. The objective of this study was to identify and analyze the socio-environmental vulnerability of the Baixada Fluminense (RJ) through two of its municipalities, São João de Meriti, and Duque de Caxias, through the elaboration of a synthesis map for each territory, called the Environmental Vulnerability Index, which integrated socioeconomic, urban infrastructure, health and public safety components, using Analytic Hierarchy Process in a Geographic Information System. The results indicated that the areas of High and Very High Socio-environmental Vulnerability are linked to the existence of precarious housing, mainly slums, which concentrate most of the vulnerable population in both municipalities. Another aspect identified as a contributor to this process was the proximity to drainage sections and the presence of sacrifice zones. The most critical areas of São João de Meriti are in the eastern part of the municipality, with a deficit of basic sanitation and high susceptibility to floods, with Vilar dos Teles being the most fragile neighborhood, which in turn concentrates a large part of the city s slums. In Duque de Caxias, which had the Campos Elíseos neighborhood as the most critical area, in addition to the slums, the inadequate conditions of basic sanitation and the great unevenness of the relief that materialize a landscape with areas at risk of large landslides and major floods.