This study examined a cultural response set to positive affect items and depressive symptom items in CES-D among 172 Korean immigrants. Bi-dimensional acculturation approach, which considers maintenance of Korean Orientation and adoption of American Orientation, was utilized. As Korean immigrants increased their American Orientation, they tended to score higher on positive affect items, with no changes occurring in depressive symptom items. Korean Orientation was not related to either positive affect items or depressive symptom items. Korean immigrants have a response bias toward positive affect items in CES-D, which decreases as they adopt more American Orientation. CES-D lacks cultural equivalence for Korean immigrants.