Background Patients with cancer commonly experience pain and suffering at the end of life days. Community-based palliative care can improve the quality of life of terminally-ill cancer patients and provide them with a merciful death. The purpose of this study was to develop an integrated model of community-based palliative care into PHC for terminally ill cancer patients. Method This study is a health system research (HSR) that was conducted in three phases from October 2016 to July 2020. In the first phase, dimensions of community-based palliative care were explored in patients with cancer using qualitative methods and conventional content analysis. In the second phase, a scoping review was carried out to complete the collected data from the qualitative phase of the study. Based on the collected data in the first and second phases of the study, a preliminary draft of community-based palliative care was developed for patients with cancer based on the framework of the World Health Organization. Finally, the developed model was validated using the Delphi technique in the third phase of the study. Results Data analysis indicated that providing community-based care to patients with cancer is influenced by the context of care. According to the developed model, patients are identified as terminally ill, and then are referred to the local comprehensive health center in a reverse manner. After patients’ referral, they can receive appropriate healthcare until death by the home care team in relation to the comprehensive health center based on the framework of primary healthcare. Conclusions This model was developed based on the current Iranian healthcare structure and the needs of terminally ill cancer patients. According to the model, healthcare is provided in a reverse manner from the subspecialty centers to patients’ homes in order to provide easy access to palliative care. It is suggested to use this model as a pilot at the regional level.