The incidence of sexual abuse of male children and adolescents is especially "invisible." Its prevalence has been reported to range between 3 percent and 31 percent (Finkelhor, Araji, Baron, Browne, Peters, and Wyatt 1986), and the number of new cases occurring each year throughout the United States has risen steadily (Dimock 1988). Finkelhor (1984) estimates that 46,000 to 92,000 male children under the age of 13 are sexually molested each year. Early indicators of child sexual abuse are difficult to assess, since they vary according to the developmental level of the victim and often differ from one child to another. Abused toddlers and preschoolers may exhibit extreme behaviors on either end of the withdrawal-aggression continuum, show precocious sexual knowledge, act out sexually with peers, or report difficulty sleeping and nightmares, often with violent or sexual content. Although withdrawal and truancy can be indicators of child sexual abuse, a sudden increase in aggressivity or a pattern of coming to school early and leaving late can also be warning signs of abuse. Effects differ within the wide range of abuse parameters. The degree of trauma experienced by child and adolescent sexual abuse victims has been found to be influenced by the sex of the offender, the closeness of the child's relationship to the perpetrator, the duration of the abuse, the severity of the abuse, and the age of the victim at onset. Elwell and Ephross (1987) observed a higher degree of trauma when sexual abuse was accompanied by the use of force and physical injury. Effects associated with male victims include somatic complaints and physical symptoms that are sexual in nature. Verbal references to ongoing abuse by male victims must always be taken seriously. There are many similarities in treatment guidelines for male and female victims of child sexual abuse; however, there are some unique differences for helpers who deal with young male victims. A prerequisite for treatment of the male sexual abuse victim is the disclosure of the experience; however, such disclosure is hampered by denial. Among group, family, and individual therapy modalities, individual therapy, especially with a male helper, can be the most difficult and intimidating for the male sexual abuse victim. In all but extreme cases in which group therapy is precluded, individual work should be done concurrently in support of group treatment. 42 references