The assessment of child sexual abuse has largely been ignored by behavior analysts, although behavior analytic theory and methodology, if applied, likely would advance the field. Three classic cases demonstrate historic errors that might have been avoided, had a behaviorally based approach been employed. Functional analytic interpretations are provided for phenomena that have been explored in a representative sample of studies that, though empirical, do not appear in the behavioral literature. Specific recommendations for practice, and a call for greater involvement of behavior analysis, are presented.