Summary Associated with the rapid growth of behavior modification as a major treatment strategy has been the use of behavioral assessment procedures. These procedures differ in method, theory, and goals from those used in traditional clinical practice. This paper surveys and critically examines the major methods of behavioral assessment, and offers recommendations to enhance their validity. The behavioral assessment methods reviewed include: observation, self-report, survey schedules, assessment for systematic desensitization, physiological measures, and assessment by operant conditioning.