The assessment of stress is a dynamic and exciting area of research. This chapter reviews the measurement of stress and begins with questionnaire and interview measures and concludes with biological measures. The measures range in complexity and difficulty from interviews that take hours to administer and score, to those as simple as a blood pressure taken in a matter of seconds. Included in this review are life events scales, semistructured interviews, self-report scales, hormonal measures, catecholamine levels, cardiovascular measures, and immune system parameters. The chapter is selective of those measures that are commonly used and have substantial literature to support their reliability and validity. Recent, innovative, and promising measures are also included such as the Adverse Childhood Experience Scale, the "D" Personality Scale, and various hormonal and immunological measures. Furthermore, principles to be considered in selecting specific measures of stress are discussed in this chapter.