OBJECTIVES: Despite the recommendation that patients with cardiovascular disease (CVD) receive bereavement care, few studies have examined the psychological disturbances in bereaved caregivers. We examined the prevalence and determinants of depression and complicated grief among bereaved caregivers of patients with CVD. METHODS: We conducted a cross-sectional survey using a self-administered questionnaire for bereaved caregivers of patients with CVD who had died in the cardiology departments of nine Japanese tertiary care centres. We assessed caregiver depression and grief using the Patient Health Questionnaire-9 (PHQ-9) and Brief Grief Questionnaire (BGQ), respectively. The questionnaire also covered caregivers' perspectives toward end-of-life care and the quality of the deceased patient's death. RESULTS: A total of 269 bereaved caregivers (mean age: 66 (57-73) years; 37.5% male) of patients with CVD were enrolled. Overall, 13.4% of the bereaved caregivers had depression (PHQ-9 ≥10) and 14.1% had complicated grief (BGQ ≥8). Depression and complicated grief's determinants were similar (ie, spousal relationship, unpreparedness for the death, financial and decision-making burden and poor communication among medical staff). Patients and caregivers' positive attitudes toward life-prolonging treatment were associated with complicated grief. Notably, in caregivers with complicated grief, there was less discussion with physicians about end-of-life care. Caregivers who felt that the patients did not receive sufficient treatment suffered more frequently from depression and complicated grief. CONCLUSIONS: Approximately 15% of bereaved caregivers of patients with CVD suffered from depression and complicated grief. Cardiologists should pay particular attention to caregivers with high-risk factors to identify those likely to develop depression or complicated grief.