Estimates of sexual victimization among boys range from 3 to 9 percent based on adult samples. Available evidence indicates that male children are more likely to be abused by nonfamily than family members. Residing in a neglectful home or a mother-headed household and having had previous homosexual contact tend to increase the risk for nonfamilial sexual abuse of boys. Familial sexual abuse of boys appears to be related to residence in a home where other siblings are being abused, where the father was a victim of sexual abuse as a child, and where parents suffer myriad personal and social adjustment difficulties. The scant writings currently available suggest that effects of male child sexual abuse may be serious and long-lasting. Reported effects have included loss of contact with reality, drug abuse, low self-esteem, guilt, poor social skills, homosexuality, other adjustment problems, and a heightened risk of becoming a sexual abuser. Compared to females, male sexual abuse victims tended to come from larger families, also be physically abused, had more force used against them, engaged in more explicitly sexual contact, and were less likely to receive counseling. 2 tables and 53 notes. (Author abstract modified)