Despite the current popularity of domestic violence treatment programs, the evaluation literature has reported mixed results in terms of effectiveness. Moreover, previous research has indicated that there are fundamental differences between self- and court-referred domestic violence offenders; such differences may have important treatment implications. As such, the current study examined differences between these two groups of offenders on three key variables: motivation to change, locus of control, and anger. Participants were 38 court-referred and 14 self-referred domestic violence offenders who were enrolled in a probation-based domestic violence program in the United Kingdom. Participants completed 3 measures: the University of Rhode Island Change Assessment-Domestic Violence (URISA-DV), the Levenson Locus of Control, and the Novaco Anger Scale. Results of statistical analyses indicated that, in comparison with court-referred offenders, self-referred domestic violence offenders scored higher on motivation to change and had higher internal locus of control. No significant differences were found between the offender groups in terms of cognitive, physiological, and behavioral experiences of anger. However, in response to anger-provoking stimuli, self-referred offenders expressed less anger, perhaps indicating that the causes of anger in domestic violence situations may be different from the causes of anger measured in the Novaco Anger Scale. The findings suggest that combining the treatment of both groups of offenders in one program may not be effective given the different levels of motivation to change. In order to explore the efficacy of joint treatment, more research must be conducted using larger samples. Tables, references