A diagnosis of cancer affects not only the patient but also their significant others, especially when a lot of care tasks are involved. Some caregivers perceive the care as a burden, while others consider it a challenge. In this article, findings concerning the impact of cancer caregiving on informal caregivers will be described. No consistent results are reported, and little is known about patterns of caregiving changes in relation to the course of the patient's illness. Attention will be given to factors which have been identified as influencing the course and consequences of caregiving. These factors form the basis of a conceptual research model for caregivers of cancer patients. As cancer progresses, care tasks are generated, which can be perceived by the caregiver as either negative (i.e. burden) or positive. Furthermore, these caregiver experiences may lead to negative as well as positive effects on the caregiver's health and these relationships can be assumed to be bidirectional.