When considering the difficulties of universalizing sanitation services in Brazil, these challenges seem even greater in small towns. This article aims to analyze the inequalities in local territorial development related to sanitation services in small towns within the Metropolitan Region of Vale do Paraíba and Northern Coast of São Paulo with populations under 50.000 inhabitants, highlighting how these disparities impact the quality of life of residents. We adopted a Dialectical Approach and a methodological procedure based on Indirect Documentary Research, using statistical data from the Brazilian Institute of Geography and Statistics and a literature review. The results revealed the challenges faced by small towns and the severity of the impact of these contrasts on the quality of life. There is an urgent need for public policies and concrete actions with a Humanistic Approach to improve the well-being of these populations and ensure universal access to basic sanitation services.