Long-term follow-up data were obtained on families who had been randomly assigned to mediate or litigate their child custody disputes. In comparison with families who litigated custody, nonresidential parents who mediated were more involved in multiple areas of their children's lives, maintained more contact with their children, and had a greater influence in coparenting 12 years after the resolution of their custody disputes. The increased involvement of nonresidential parents who mediated did not lead to an associated increase in coparenting conflict. Parents who mediated also made more changes in their children's living arrangements over the years. For the most part, the changes apparently reflect increased cooperation and flexibility. Satisfaction declined for parents (especially fathers) in both groups over time, but fathers remained much more satisfied if they mediated rather than litigated custody. Few differences in satisfaction were found between mothers in the 2 groups. The 12-year follow-up data indicate that, even in contested cases. mediation encourages both parents to remain involved in their children's lives after divorce without increasing coparenting conflict.