In this chapter, we review the use of neuropsychologic assessment in epidemiologic studies. First, we provide a brief introduction to the history of clinical neuropsychology and neuropsychologic assessment. We expand on the principal components of a neuropsychologic assessment and cognitive domains most commonly examined. This chapter also seeks to highlight specific domains and tests with validated psychometric properties that are widely accepted in clinical practice, as well as how data from a neuropsychologic test should be interpreted. Additionally, the important roles that neuropsychologic assessments play in tracking normative changes, patient diagnoses, care, and research will be discussed. Factors to consider when deciding on the inclusion of test instruments for a research study will also be reviewed. Lastly, we shed light on the contributions that neuropsychology has played in epidemiologic studies, as well as some challenges frequently faced when participating in this field of research.