This study assessed the types of health care services used by Korean immigrants, and differences in use between different countries, genders, health insurance status, acculturation status, and cardiovascular risk. Participant selection used probability sampling to represent the adult populations of California, United States, and Seoul, Republic of Korea. A telephone survey was administered to 2830 adult Korean-Californians and 500 adult Koreans living in Seoul. Female gender was significantly associated with higher use of outpatient services, ER usage, and hospitalization. Californian residence was significantly associated with higher outpatient usage and lower hospitalization rates. Health insurance was associated with higher allopathic health care utilization, and lower traditional health care usage, and acculturation with lower traditional health care usage. Higher self-reported cardiac risk factors were associated with lower allopathic and higher traditional health care. This suggests barriers to allopathic health care, but not traditional health care, for Koreans living in California without health insurance.