A total of 120 undergraduate college students (61 males and 59 females) enrolled in introductory psychology and other general education courses at a mid-sized eastern university participated in the study. Ninety-one percent of the respondents were White, and 79 percent had lived with both their biological or adoptive mother and father for most of their childhood. To be eligible for participation, the students were required to have at least one sibling, to be unmarried, and to have been involved in heterosexual dating relationships. Participants were administered the Scale of Negative Family Interactions, the Conflict Tactics Scale (Parent-to-Child Version), the Conflict Tactics Scale (Standard Version), and the Sexual Experiences Survey. For males, dating violence was associated with abuse by older and younger brothers and sisters. For females, dating violence was linked with abuse by older siblings but not by younger siblings. Dating violence among males was more strongly associated with sibling abuse than with parental abuse. In contrast, dating violence for females was more strongly associated with abuse by parents. Emotional and physical aggression by parents and siblings were associated with expressed emotional dating violence among males and with expressed physical dating violence among females. The findings thus support the hypothesis that abuse by siblings, like abuse by parents, may contribute to a cycle of violence in the lives of those abused by siblings. 3 tables and 37 references