Objective: To adequately help family caregivers (FCs) of cancer patients, clinicians need to understand the complexity of the problems and responsibilities associated with cancer patients illness that FCs experience. Methods: This systematic review identified the types of problems and burdens that FCs of cancer patients experience during the patient's illness. We also analyzed the language caregivers use to communicate their problems and responsibilities related to caregiving for the cancer patient. Results: Of 2845 titles identified, 192 articles met the inclusion criteria and are included in this review. Of these, 164 were research-based. In addition to FC responsibilities and the impact of being a caregiver on daily life, a number of other physical, social, and emotional problems related to caregiving for these FCs were identified. Conclusion: A substantial evidence base supports the conclusion that FCs experience many difficult problems and increased responsibilities during and after the patient is undergoing treatment and rehabilitation for cancer. The insights gained from this review will help researchers and clinicians to understand the complexity of problems and responsibilities FCs experience. This understanding may encourage them to include support for FCs as part of total or holistic patient care. However, more research is needed to better understand the variations in caregiving experiences over time; how the caregiving perspective is influenced by different cultural, ethnic, or socioeconomic backgrounds as well as gender and age; and how problems and responsibilities related to caregiving interfere with daily life. Copyright © 2009 John Wiley & Sons, Ltd.