In many states, mediation is mandatory in all child custody disputes. However, investigations have indicated that mediation may be inappropriate in cases involving domestic violence, as victims are greatly disadvantaged. This study looked at information from 400 randomly selected mediation reports, half of which involved domestic violence, either as evidenced by clear indicators such as current allegations or temporary restraining orders, or as identified by the mediator during the course of mediation. The results indicated that in many cases involving violence, mediators failed to address the issue during mediation at all. Further, the presence of violence made surprisingly little difference when determining legal and physical custody of children, and in some situations actually increased the likelihood of custody for the perpetrator. Overall, the presence of substance abuse or psychiatric treatment had a much more significant effect on custody decisions than domestic violence.