Of these children, 69 percent had been abused by a member of their psychosocial family, and almost 26 percent had been abused by someone outside the family. With the exception of State-support (more frequent among incest families), the two groups did not differ significantly on a variety of child, parent, and family variables. For both groups, 65 percent of the abuse involved oral, vaginal, or anal penetration; force was the modal strategy. Compared to extrafamilial victims, incest victims were significantly more likely to have suffered multiple abuses, to have been abused for a year or longer, and to have disclosure of the abuse disbelieved by their mothers. Extrafamilial abusers were more likely to be arrested and prosecuted than were family members. State protective services were involved in incest cases for longer times, and children were more likely to receive out-of-home placements, particularly in cases where mothers did not believe in the abuse. Incest families were more likely to be referred for mental health treatment, were less engaged in treatment, and accomplished fewer of their treatment goals. 27 references.