Most men were mandated to the batterer programs by the courts (82 percent), as opposed to others who entered the batterer programs voluntarily (18 percent). The men tended to be fairly young and of a lower socioeconomic status. Data were collected using questionnaires that included items on the incident leading to participation in the batterer program and on physical aggression. The men's partners were interviewed by telephone within 2 weeks of the men's program intake. Both men and their female partners were called separately every 3 months for a 15-month follow-up period and were interviewed about their relationship status, behavior toward partner, alcohol and drug use, and other treatment and assistance received. Results showed about half the batterers perceived jailing as likely to result from program drop-out or re-assault. Batterers from programs with a court review process for program compliance and/or higher arrest rates for re-assault were more likely to perceive jail as likely. Results also supported the experiential effect of prior contact with the criminal justice system and alcohol treatment. However, neither perceived certainty of sanctions (jailing likely) nor perceived severity of sanctions predicted drop-out and re-assault. The authors conclude increasing perceptions of criminal justice sanctions alone may not prevent batterers from re-assault. 40 references, 1 note, and 4 tables