Despite the growing number of Korean American (KA) family caregivers for persons with dementia, little is known about how acculturation might affect caregiving stress in this population. Acculturation is a variable of considerable interest in caregiving research due to its significance in understanding the impact of cultural perceptions and expectations on the caregiving role and its relation to mental health outcomes. A cross-sectional descriptive study using baseline data from an ongoing randomized controlled trial of dementia caregiver intervention was performed to examine the association between acculturation and mental health outcomes among KA caregivers (n = 32) for persons with dementia. Self-report survey questionnaires including a bidirectional acculturation scale, Center for Epidemiologic Studies Depression Scale, the Perceived Stress Scale, and the Zarit Burden Interview were administered in person in English or Korean by trained bilingual community health workers. The primary independent variable, acculturation, was assessed using a 24-item inventory. It measured two sets of cultural orientation: Korean orientation and American orientation. The mean age was 67 years (SD = 11.8) and 87% were women. Half of the caregivers were spouses of persons with dementia, while the other half were offspring caregivers. In the multiple linear regression model, caregiver acculturation toward Korean cultural orientation had a significant and positive association with depressive symptoms (β = .62; SE = 0.25; p-value = .02) and perceived stress (β = .29; SE = 0.13; p-value = .03) after adjusting for age and self-efficacy. No significant effect of American cultural orientation was found for caregiver burden, perceived stress, or depressive symptoms. Our findings suggest that exploring the role of acculturation in caregiving and its relation to outcomes, particularly caregiver distress, may be valuable for future studies aiming to understand specific elements of cultural values and practices in the acculturation process related to mental health outcomes among immigrant Korean American caregivers.