Interparental conflict is one of the primary risk factors for negative outcomes for children whose parents separate, and it is likely to be high while parents are separating. Results are mixed regarding the effectiveness of interventions aimed at reducing interparental conflict. This study examined co-parents who were court-ordered to attend a 12-hr co-parenting intervention and completed pre–postassessments (n = 20) and 2-month follow-up assessments (n = 17). The results demonstrated increases in co-parents’ relationship functioning and confidence in co-parenting. Both men and women reported decreased amounts of conflict in the presence of their children; however, only women reported decreases in general negative communication with the co-parent. These changes were generally maintained at a 2-month follow-up assessment. These findings suggest that interventions for high-conflict co-parents may increase their ability to work cooperatively.