Background: Strong family bonds are part of the Indonesian culture. Family members of patients with cancer are intensively involved in caring, also in hospitals. This is considered "normal": a societal and religious obligation. The values underpinning this might influence families' perception of it.; Aim: To explore and model experiences of family caregivers of patients with cancer in Indonesia in performing caregiving tasks.; Design: A grounded theory approach was applied. The constant comparative method was used for data analysis and a paradigm scheme was employed for developing a theoretical model.; Setting/participants:: The study was conducted in three hospitals in Indonesia. The participants were family caregivers of patients with cancer.; Results: A total of 24 family caregivers participated. "Belief in caregiving" appeared to be the core phenomenon. This reflects the caregivers' conviction that providing care is an important value, which becomes the will power and source of their strength. It is a combination of spiritual and religious, value and motivation to care, and is influenced by contextual factors. It influences actions: coping mechanisms, sharing tasks, and making sacrifices. Social support influences the process of the core phenomenon and the actions of the caregivers. Both positive and negative experiences were identified.; Conclusion: We developed a model of family caregivers' experiences from a country where caregiving is deeply rooted in religion and culture. The model might also be useful in other cultural contexts. Our model shows that the spiritual domain, not only for the patient but also for the family caregivers, should be structurally addressed by professional caregivers.