A person living with cancer will potentially have some degree of physical, cognitive, and/or psychological impairment, periods of unemployment, financial concerns, social isolation, and existential questions, any or all of which can impact the family and friends who surround them. In our current era of health care, patients with cancer receive invasive diagnostic studies and aggressive treatment as outpatients, and then convalesce at home. As such, cancer family caregivers are de facto partners with the healthcare team. The cancer family caregiver role is demanding and may lead to increased morbidity and mortality-in effect, the cancer family caregiver can become a second patient in need of care. This chapter discusses the consequences cancer family caregivers may accrue. The topics covered include caregiver mood disturbance and psychological impairment and some of the mutable factors that contribute to these states (i.e., sleep disturbance, decline in physical health, restriction of activities, and financial concerns), uncertainty, spiritual concerns, and caregiver witnessing. There is a discussion of the factors that influence the caregiving experience (caregiver characteristics, patient characteristics, and social supports). The chapter concludes with comments on intervention studies that have been conducted to ameliorate the burden of caregiving, and the state of caregiver research.