There is extensive theoretical and empirical evidence linking substance abuse and marital violence. However in batterer populations, researchers have not compared hazardous and nonhazardous drinkers' substance use characteristics, marital aggression, extramarital violence (i.e., general violence), depressive symptomatology, marital satisfaction, and other relevant variables. In addition, much of the previous research on substance use and abuse in batterer populations employed a single, nonstandardized measure of substance use, and no previous research has examined substance use in court-mandated batterers' relationship partners. We recruited 150 men who were arrested for violence and court-referred to batterer intervention programs. We administered multiple measures of substance use and abuse and assessed the batterers' marital aggression, relationship satisfaction, depressive symptomatology, use of general violence, and their relationship partners' substance use. We also divided the sample into groups of Hazardous Drinkers (HD) and Nonhazardous Drinkers (NHD). Across the entire sample, half of the batterers had an alcohol-related diagnosis and approximately one third reported symptoms consistent with a drug-related diagnosis. Over one third of the total sample reported that their relationship partners were hazardous drinkers. Relative to the NHD group, the HD group scored significantly higher on measures of general violence, depressive symptomatology, alcohol use, alcohol problems, and drug problems. The HD group also reported significantly higher partner alcohol and drug use and abuse scores, relative to the NHD group. The results of the study suggest that substance use and abuse should routinely be assessed as part of batterer interventions and that batterer programs would be improved by offering adjunct or integrated alcohol treatment.