Quality of life (QOL) of the Hospitalized psychiatric patients becomes an indicator of nursing care effectiveness. This study aimed to explore the QOL and its associated factors of those chronic and hospitalized mentally ill patients. 150 patients were recruited from a psychiatric teaching hospital in Hualien in Taiwan. Instruments included patients' demographic information, social support scale, and QOL scale. The results revealed that the participants scored 74.11 (out of 135) in QOL. The main associated factor is vocational rehabilitation, particularly, the patients having paid jobs had higher QOL. We suggested to develop suitable vocational rehabilitation to improve the chronic and hospitalized patients' QOL, and to help them return to the community.