This study examines whether intervention-induced changes in mother–child relationship quality and discipline led to short-term (6 months) and long-term (6 years) changes in children’s coping processes in a sample of 240 youth aged 9–12 years when assessed initially. Data were from a randomized, experimental trial of a parenting-focused preventive intervention designed to improve children’s postdivorce adjustment. Three-wave prospective mediational analyses revealed that intervention-induced improvements in relationship quality led to increases in coping efficacy at 6 months and to increases in coping efficacy and active coping at 6 years. Tests of the mediated effects were significant for all 3 indirect paths. Results are discussed in terms of pathways to adaptive coping and implications for the implementation of preventive interventions targeting coping.