The effects of legal custody arrangement and quality of the co-parental relationship on the adjustment of adolescents in remarried families was examined. Joint custody was associated with better relationships with step-parents and more family cohesion. Girls in sole custody families and boys in joint custody families reported high anxiety. Girls in sole custody families reported the remarriage to have a negative effect on their relationships with their custodial biological parents. Hostility in the co-parental relationship was associated with more loyalty conflicts and more increase in psychosomatic and psychosocial problems around the time of the remarriage.