Hostility may contribute to risk for disease through psychosocial vulnerability, including the erosion of the quality of close relationships. This study examined hostility, anger, concurrent ratings of the relationship, and change in marital adjustment over 18 months in 122 married couples. Wives' and husbands' hostility and anger were related to concurrent ratings of marital adjustment and conflict. In prospective analyses, wives' but not husbands' hostility and anger were related to change in marital adjustment. In hierarchical regression and SEM models wives' anger was a unique predictor of both wives' and husbands' change in marital adjustment. The association between wives' anger and change in husbands' marital satisfaction was mediated by husbands' ratings of conflict in the marriage. These results support the role of hostility and anger in the development of psychosocial vulnerability, but also suggest an asymmetry in the effects of wives' and husbands' trait anger and hostility on marital adjustment.