There are many psychiatric consequences of severe and debilitating diseases. Psychiatric disorders are therefore commonly present after a physical illness. The purpose of this study was to investigate the process of acceptance of illness in patients with incurable diseases. The conceptual research framework was based on Kübler-Ross's theory of acceptance of illness. In this qualitative research, a guided approach to content analysis has been used. This study was carried out using semi structured interviews based on theoretical saturation with 15 patients with incurable diseases. The results of this study have shown that patients with incurable diseases have passed seven stages of death acceptance: shock disease, coping strategies, disease denial, anger, depression, referral group reactions, and acceptance of illness. Considering the need to recognize the process of accepting the disease in patients with incurable disease, the results of this study may be useful for those patients involved in treating the disease correctly. Furthermore, the results of this study can be used by researchers, managers, and planners to enhance their knowledge of incurable patient needs and evidence-based planning.