Although child protective agencies have the statutory authority and responsibility for validating complaints of child sexual abuse, every professional working with children should be aware of the essential elements of the process. Validation depends on the ability to interpret behavior, physical signs, and information elicited from investigative interviews. Behavioral signs, which may occur in combination, can range from overly compliant behavior to aggressive behavior and from running away from home to suicidal feelings. Physical indicators may be trauma to the genital or rectal area as well as pregnancy. However, most victims do not show physical signs; still, a physical examination should be conducted in every case of suspected abuse. In conducting investigative interviews, the professional should establish credibility, use an appropriate setting, use terminology appropriate to the child, diffuse anxiety, and be aware of the child's sense of time. The interviewer should also be aware that the first reported incident is rarely the first incident and should try to determine both the duration and the type of sexual abuse. The four phases of interviewing are establishing a relationship with the child, determining the facts, examining the elements of the situation which determine if the child will be safe after the disclosure, and planning for intervention. Assessing the credibility of the report follows the factfinding phase. Guidelines for the medical examination and five references are included.