We explore the relationship between couples' stable personality variables associated with interpersonal competencies (referred to here as relationship personality variables) and marital satisfaction with conflict resolution style as the mediating factor. Eighty-three newlywed couples participated in the study at 6 points over 5 years at 1-year intervals. The results indicate strong mediational effects across time. In particular, conflict resolution styles appear to form during the 1st year of marriage and are habituated thereafter to a large extent. The relationship personality variables correspond closely with conflict resolution styles, which in turn influence marital satisfaction. The implications for intervention, especially for preventive intervention in early marriage, are presented.