The purpose of this study was to explore the effects of older brother-younger sister incest from the perspective of the women who experienced it in childhood or adolescent years. Dynamics in the families-of-origin were also explored, as these related or contributed to the effects from the incest. Seventeen women were interviewed, using an in-depth, semi-structured interview. Four self-report objective instruments were also administered that measure dynamics in the family-of-origin and symptomatology that is often associated with the effects of trauma. Interview and objective data were analyzed by systematically organizing the women's perceptions and conceptualizations into common themes. All of the women's families of origin were described as dysfunctional. Common effects reported included mistrust of men and women, chronic low or negative self-esteem, sexual response difficulties, and intrusive thoughts of the incest. Women regarded individual therapy, talking with supportive family and friends, and validating themselves as victims at the time of the incest as ways in which they have helped themselves to deal with the effects of the incest. These results have important implications for therapy, including serious consideration of the impact and contribution of this kind of incest on reported symptomatology, and on emerging issues and conflicts in the therapeutic process.