Families of patients receiving palliative care are profoundly affected by the challenges of the illness. They observe care that the patient receives, provide care for the patient, and receive support from health professionals in the form of information, counselling, or practical assistance. As they witness and participate in the patient's care, they judge the quality of care that the patient receives. They often see themselves as the patient's care advocates and may harbour regret and guilt if they believe that the patient did not have the best possible care. The illness experience profoundly affects family members' psychological and physical health; recognition of this has coined the term "hidden patients." This article briefly synthesizes empirical work that suggests how to best support families in a palliative care context. We discuss how to define the family, emphasizing a systems approach to family care. We describe the impact of the illness on the family in terms of family members' health, family communication issues, psychological issues, needs for information, physical care demands, and family costs of caring.