Objective: The purpose was to gain insight in the functioning of caregivers of cardiac arrest survivors at 12 months after a cardiac arrest. Secondly, the course of the wellbeing of the caregivers during the first year was studied. Finally, factors that are associated with a higher care burden at 12 months after the cardiac arrest were investigated. Subjects: A total of 195 family caregivers of cardiac arrest survivors were included. Main measures: Quality of life (SF-36, EuroQol-VAS), caregiver strain (CSI) and emotional functioning (HADS, IES) were measured at two weeks, three months and one year after the cardiac arrest. Thereby, the caregiver was asked to fill out the cognitive failure questionnaire (CFQ) to evaluate their view on the cognitive status of the patient. Results: Caregiver strain was high in 16 (15%) of the caregivers at 12 months. Anxiety was present in 33 (25%) caregivers and depression in 18 (14%) caregivers at 12 months. The repeated measures MANOVA showed that during the first year the following variables improved significantly: SF-36 domains social and mental health, role physical, role emotional and vitality, caregiver strain, HADS and IES (P<0.001). At 12 months caregiver strain correlated significantly (explained variance 63%, P=0.03) with caregiver HADS (P=0.01), EuroQol-VAS (P=0.02), and the CFQ (P<0.001), all measured at 12 months after the cardiac arrest. Conclusions: Overall wellbeing of the caregivers improves during the first year up to normal levels, but caregivers with emotional problems or perceived cognitive problems at 12 months are at risk for developing a higher care burden.