The cases had all been referred to a child protection agency by the mother. Six of the mothers had experienced childhood abuse by the perpetrator of the abuse of the current child victim. Only 2 of the 18 grandchildren who had been sexually abused showed no symptoms at the time of the report. Victims from families in which both parents and grandparents were divorced had severe educational and behavioral problems. Victims from stable families showed fears and phobias. Eight of the victims had been victimized by more than one perpetrator. Findings called into question the assumption that grandparent incest is a benign form of abuse and indicate some justification for the fears expressed by adult incest victims about visits between their children and their father-perpetrators. Tables and 13 references. (Author abstract modified)