A qualitative study was conducted in an attempt to improve our understanding of the spiritual distress of terminally ill cancer patients in Japan. The subjects were inpatients at four approved palliative care units in Japan. The patients were interviewed and they expressed their own experiences in which spirituality was considered to be identifiable. Literal records of the interviews were analyzed using constant comparative analyses as proposed in relation to the grounded theory approach. The analysis included 11 inpatients and a variety of expressions of distress were obtained. After the conditions of the subjects were evaluated in order to search for common factors related to distress, consciousness of the gap between the patient's aspirations and the present situation were found to cause gap-induced distress. Distress was classified into three categories: distress due to the gap between the present situation and how the individual wanted to live, how the individual wished to die, and the individual's wish to maintain relations with others. The aspirations causing the gap were then interpreted from the viewpoint of spirituality as "anchors in life" for Japanese patients with terminal cancer. It was also revealed that in patients who possessed pictures of how they wished to die as their "anchors in life" and who were in a severe physical condition, distress increased and they became confused after their physical symptoms were relieved following admission to PCU.