Quality of life (QoL) research has increased during last decates. Psychiatric patients spend many days for their treatment so QoL is something that should be measured for these patients too.

To examine the relationship between dispositional optimism and Quality of life (QOL) among patients suffering from schizophrenia, schizoaffective disorder, bipolar disorder, depression, and other psychiatric conditions from a psychiatric department and to find out the existing correlations with other measures of personality characteristics.

To reveal the underlining correlation between QoL and dispositional optimism.

69 inpatients in a psychiatric ward in Athens-Greece took part in the study.31 (44.9%) of them were males and 38 (55.1%) females. The questionnaires that were used are the Short Form health questionnaire (SF12), the life orientation test-revised (GrLOT-R), the subjective well being scale (SWBC) and the Satisfaction with life Scale(SWLS).

Both Physical (M=39,9 SD=±7,2) and Mental (M=29,4 SD=±7,8) composite scores are lower than in the greek general population (M=50 SD=±6,8). Optimism (M=14,8 SD=±4.9) correlates significantly with both mental (p=,571^**) and physical (p=,438^**) health, well being (p=,427^**) and with the days of hospitalization (p=.,261^**). Global happiness correlates significantly only with mental health (p=,493^**) and well being (p=,573^**).

Quality of life in mental patients seems to have a mediator and that is Optimism. Optimistic patients seems to have better health related quality of life and well being and stays more days in hospital for treatment needs.