There is a growing recognition that the similarities between older adults and family caregivers has both practical and research implications; caregivers' well-being influences older adults' well-being and vice versa. There has been a paucity of studies that explore the similarities between Korean older adults and their caregivers. This study aims to examine psychological, physical, social, and spiritual well-being similarities among 157 older adult-caregiver dyads in Seoul, Korea. There was a significant degree of similarities between older adults and their caregivers with respect to psychological, social, and spiritual well-being, but not to physical well-being. Present findings suggest that nurses and other health care professionals should be involved and collaborate with family caregivers to take care of older adults; to understand the dynamic, caring relationships between older adults and their family caregivers; and to improve the well-being of older adults as well as their family caregivers.