Objectives: Available data suggest high burden on caregivers of patients with bipolar disorder (BD), yet the well-being of patients with BD increasingly depends on family members, partners and close friends. As patients with BD get older, the need for informal care may shift. We aimed to describe the caregivers of older adults with BD (OABD) and explore what patients' and caregivers' characteristics are associated with caregiver burden. Method: Forty-seven caregivers of OABD were questioned about their perceived burden and depressive symptoms. Linear regression analyses were performed to examine the influence of various patients' and caregivers' characteristics on caregiver burden or depression. Results: More than half of all caregivers experienced some degree of burden, and 6.4% reported depressive symptoms. The number of psychiatric admissions and social functioning were the only patients' characteristics associated with higher burden. Caregiver burden was significantly associated with caregiver's other obligations. None of the patient or caregiver characteristics was significantly associated with depression in caregivers of OABD. Conclusion: In OABD, even with few residual symptoms, more than half of all caregivers experience substantial burden. Future studies are needed to confirm if improving social functioning and preventing psychiatric hospitalizations decrease the burden on the caregivers of OABD.