In a study involving 160 undergraduates, we tested the hypothesis that attributional style and defense style would have interactive effects on depressive symptoms. Consistent with this hypothesis, both negative attributional style and low defense maturity were associated with depressive symptoms, both as main effects and in interaction. Negative attributional style was associated with depressive symptoms primarily when accompanied by low defense maturity. The presence of a positive attributional style reduced the relation between low defense maturity and depressive symptoms, and the presence of high defense maturity reduced the relation between a negative attributional style and depressive symptoms. In addition, high defense immaturity was shown to be a possible mediator of the relation between negative attributional style and depressive symptoms. Clinical implications for psychotherapy integration are discussed.