To determine an underlying factorial structure of existential distress in Japanese terminally ill cancer patients, a principal components analysis was performed on 162 Japanese hospice inpatients. Existential distress commonly identified was dependency (39%), meaninglessness in present life (37%), hopelessness (37%), burden on others (34%), loss of social role functioning (29%), and feeling emotionally irrelevant (28%). By a factor analysis, three primary components accounted for 66% of the variance. 'Dependency' and 'loss of social role functioning' loaded highly on the first factor, which was interpreted as 'loss of autonomy'. 'Burden on others' and 'feeling emotionally irrelevant' loaded highly on the second component interpreted as 'lowered self-esteem', while 'hopelessness' loaded highly on the third factor. On the other hand, 'meaninglessness in present life' loaded equally on all three components, and was significantly associated with other distress. In conclusion, existential suffering of Japanese terminally ill cancer patients has three principal components: loss of autonomy, lowered self-esteem, and hopelessness. It is also suggested that meaninglessness in present life would be an underlying theme in patients' spirituality.