OBJECTIVE: To improve understanding of the nature and magnitude of the burden of informal care and also to indicate important areas for improving the current ways in which informal care is investigated. METHODS: Information on objective burden (such as care tasks performed and time investment), subjective burden (using the Caregiver Reaction Assessment instrument and a self-rated burden score), and quality of life (using the EuroQoL instrument) were collected in a postal questionnaire of 153 informal caregivers who provide care for rheumatoid arthritis (RA) patients. RESULTS: Caregivers had been caring for the RA patients on average for >11 years, reflecting the chronic nature of RA. They provide a substantial amount of care (27.4 hours per week) and are moderately strained (24.6 on the self-rated burden scale). Caregivers are relatively healthy on average but caregivers of more severe RA patients are relatively unhealthy, which may indicate health losses due to caregiving. CONCLUSION: Informal care can be burdensome in the context of RA. More information may help assist informal caregivers in caring for RA patients and help to avoid health problems and high subjective burden.