Child sexual abuse is a serious, pervasive problem with clinical, social, moral, and legal implications. Between 100,000 and 500,000 children in the United States are thought to be sexually molested annually. Physicians in all specialties may detect sexual exploitation of youngsters and are mandated to report such cases. Failure to diagnose child molestation and pedophilia and to treat their cause can have serious, long-lasting consequences for innocent victims and continued distress for the perpetrator and for the professional who missed the diagnosis. A single child molester may commit hundreds of sexual acts on hundreds of children. The etiology of paraphilic syndromes is multifactorial. There are substantial differences among sexual abusers of children in their personalities and psychopathologies. Although available interventions are symptomatically palliative rather than curative, many pedophiles can benefit from appropriate treatment. Primary prevention may be the key to reducing the frequency of child sexual abuse.