This study examines the psychosocial, occupational, and economic impact of caregiving for patients with advanced breast cancer. It follows 89 caregivers of women with advanced breast cancer receiving care at either the Ottawa or Hamilton regional cancer centres in Ontario. Patients were followed until their death or study completion at 3 years. Caregivers identified by patients were assessed at regular intervals during the palliative and terminal periods. The study used standardized validated instruments to measure caregiver and patient health status, psychological distress, burden, and social support. Caregivers were predominantly male (55%) and the patient's spouse or partner (52%), with a mean age of 53 years. At the start of the palliative period, caregivers had better physical functioning scores than patients. Caregivers were more likely to be anxious and depressed than patients. Caregiver burden was the most important predictor of both anxiety and depression. Over half of the caregivers were employed, and 69% reported some form of adverse impact on work. In the terminal period, 77% of caregivers missed work due to caregiving responsibilities. Prescription drugs were the most significant component of financial burden. Caregivers experienced substantial psychological morbidity (anxiety and depression) at the onset of the patient's palliative illness and a substantial increase in caregiver burden and depression when the patient reached a terminal stage. Caregiver burden was the most important predictor of both caregiver anxiety and depression. The study highlights the need for strategies to reduce the psychosocial, occupational, and economic burden associated with caregiving. The findings underscore the importance of implementing recommendations for income security and job protection for family caregivers. The study also supports the need for policies addressing the growing impact of drug costs on patients and their families. The study has limitations, including the complexity of conducting palliative care research and the potential for small changes in caregiver burden to be missed. Despite these limitations, the study provides important insights into the challenges faced by caregivers of patients with advanced breast cancer.This study examines the psychosocial, occupational, and economic impact of caregiving for patients with advanced breast cancer. It follows 89 caregivers of women with advanced breast cancer receiving care at either the Ottawa or Hamilton regional cancer centres in Ontario. Patients were followed until their death or study completion at 3 years. Caregivers identified by patients were assessed at regular intervals during the palliative and terminal periods. The study used standardized validated instruments to measure caregiver and patient health status, psychological distress, burden, and social support. Caregivers were predominantly male (55%) and the patient's spouse or partner (52%), with a mean age of 53 years. At the start of the palliative period, caregivers had better physical functioning scores than patients. Caregivers were more likely to be anxious and depressed than patients. Caregiver burden was the most important predictor of both anxiety and depression. Over half of the caregivers were employed, and 69% reported some form of adverse impact on work. In the terminal period, 77% of caregivers missed work due to caregiving responsibilities. Prescription drugs were the most significant component of financial burden. Caregivers experienced substantial psychological morbidity (anxiety and depression) at the onset of the patient's palliative illness and a substantial increase in caregiver burden and depression when the patient reached a terminal stage. Caregiver burden was the most important predictor of both caregiver anxiety and depression. The study highlights the need for strategies to reduce the psychosocial, occupational, and economic burden associated with caregiving. The findings underscore the importance of implementing recommendations for income security and job protection for family caregivers. The study also supports the need for policies addressing the growing impact of drug costs on patients and their families. The study has limitations, including the complexity of conducting palliative care research and the potential for small changes in caregiver burden to be missed. Despite these limitations, the study provides important insights into the challenges faced by caregivers of patients with advanced breast cancer.