This article analyzes the relationship between incidences of hepatitis A — a water-borne disease that can also be transmitted by lack of hygiene — and quality indicators in the provision of water supply services, through secondary data extracted from the National Information Systems for Notifiable Diseases and on Sanitation, in the period between 2007 and 2018, for the municipalities of the State of Rio de Janeiro, Brazil. The indicators were initially submitted to Principal Component Analysis (PCA) to reduce numerous variables that showed autocorrelation with each other. Subsequently, the principal components were submitted to Pearson’s correlation analysis with the incidence of hepatitis A. A correlation coefficient of -0.32 was observed, at the level of significance (p < 0.05) between the cumulative incidences of hepatitis A and the principal component (PC3) formed by a set of quality indicators for the provision of water supply services. The indicators that best described PC3, with factor loadings ranging from -0.88 to 0.70, were those related to: hydrometer, water and revenue losses, water revenue, the participation of residential water savings, micro-measurement related to water consumption, water consumption and average water consumption per economy, average duration of outages, and the incidence of non-standard total coliform analyses. Thus, the observed results point to an association between the quality of water supply services and the incidence of hepatitis A, which may indicate both failures in treatment efficiency and lack of hygiene.