Children of alcoholics have been identified as an at-risk population for a number of physical, emotional and behavioral problems. Therefore, accurate identification of this potential client group is important for both prevention and intervention programming. The current study investigated the psychometric properties of the Children of Alcoholics Screening Test (CAST), which was developed as an assessment tool for identifying latency-age, adolescent and adult children of alcoholics. Respondents were recruited through the use of nominational sampling methods for participation in this cross-sectional study. The study sample was composed of 65 male and 149 female respondents, including both adult children of alcoholics (ACOAs) and adults reared in non-substance-abusing homes (non-ACOAs). Both ACOA (n = 140) and non-ACOA (n = 74) groups included clinical and nonclinical subjects. Respondents completed a mailed, self-report survey that included the CAST, five other standardized instruments measuring family and personal functioning, and sociodemographic questions. Study findings indicated that the CAST is unidimensional, possesses excellent reliability (alpha = .98) and has a low standard error of measurement. Support was also shown for several types of measurement validity, including discrimination validity, factorial validity and construct validity. Data from the current study support use of the CAST as a reliable and valid instrument that may be employed in both research and clinical practice.