Criminologists have long noted that offenders are more likely to be the victims of crime as compared to nonoffenders. What has not been established, however, is why there is a significant degree of victim–offender overlap. While numerous explanations have been advanced and a significant number of studies have been conducted, there remains much to be learned about the etiology of the victim–offender overlap. The current study pushes this line of research forward by offering and testing a unique hypothesis: that victimization and offending share a genetic etiology that leads to victim–offender overlap. Findings culled from a sample of sibling pairs drawn from the National Longitudinal Study of Adolescent Health indicated that genetic factors explained between 51% and 98% of the covariance between victims and offenders. Nonshared environmental factors explained the remaining covariance, while shared environmental factors explained none of the covariance. Implications and interpretations of these findings are considered.