The author reviewed measurement of quality of life (QOL) of schizophrenia patients and the clinical factors related to their QOL. As schizophrenia patients were thought to be unable to assess their own QOL because of their cognitive impairment, objective QOL measures had been frequently used. However, nowadays, there is general agreement that symptomatically stabilized patients could assess their QOL by themselves. Therefore, researchers gradually have become interested in subjective QOL measure. Although most researchers often evaluate schizophrenia patients’ QOL using only subjective or objective QOL measure, considering the fact that there is a discrepancy between the two types of measures, it is recommended to use both of them as complementary measures. As for clinical factors related to lowered QOL, several studies reported that depressive symptom was most associated with lowered subjective QOL, negative symptom was strongly related to lowered objective one and poor life skill was associated with both. Moreover, several studies found that cognitive dysfunctions in some cognitive domains were related to lowered objective QOL but the effects of them were much smaller than those of negative symptoms. It is suggested that improving depressive and negative symptoms and life skills may contribute to enhancement of QOL of schizophrenia patients. J. Med. Invest. 58: 167-174, August, 2011