Through the increased use of evidence-based toxicology (EBT) methods, the incorporation of epidemiological data in chemical assessment has expanded considerably. However, accurate characterization of exposure/adverse health outcome relationships from observational studies is often complex since exposures are time-dependent and adequate exposure concentration data are limited. Correspondingly, other lines of evidence such as animal data and new approach methodologies (NAMs) have their own limitations. Thus, the need to integrate data across all realms of relevant evidence (i.e., animal, epidemiological, mechanistic) and capture the uncertainty within remains at the forefront of regulatory decision making. This introduction will provide an overview of the session and open the discussion regarding the integration of epidemiological, animal, and NAMs evidence to bolster decisions for causal conclusions.