This article reviews prevention programs that target primary residential parents as change agents for improving children's postdivorce adjustment. First, we review parental risk and protective factors for children from divorced families, including parenting quality, parental mental health problems, interparental conflict, and contact with the nonresidential parent. Following a discussion of brief informational interventions, we describe the findings of evaluations of three multisession, skill-building interventions for divorced parents. Impressive evidence is presented that parenting is a modifiable protective factor and that improving parenting leads to improvements in children's postdivorce adjustment. We then discuss, in greater detail, the New Beginnings Program, which we highlight because it has shown repeated, immediate effects on children's mental health outcomes as well as long-term effects on a wide array of other meaningful outcomes, such as diagnosis of mental disorder in the past year, externalizing problems, alcohol and drug use, and academic performance. Also, mediational analyses have shown that program-induced changes in parenting accounted for changes in mental health outcomes. The remainder of the article describes a research and action agenda that is needed to successfully implement the New Beginnings Program in domestic relations courts.