Introduction & Objective: Cancer patients face with psychosocial and physical problems that may have an impact on the patient's quality of life .The purpose of this study was to investigate the relationship between mental health and quality of life in cancer patients.

Materials & Methods: This study is a cross-sectional and correlation research .In this study , 90 patients that referred to Shafa hospital in Ahvaz were selected through convenient sampling in 2008. Data were collected by general health questionnaire and short form quality of life questionnaire (Sf-36) and were analyzed using Spearman's correlation, independent t-test and one way ANOVA.

Results: The results showed that most domains in quality of life were correlated with mental health domains. General health perception and physical function domains were correlated significantly with 3 domains of mental health: anxiety ,social function and depression. Somatoform symptoms were significantly correlated with mental health domain of quality of life (P<0.02). Finally, social function was significantly correlated with social dysfunction domain of life quality (P<0.05). Also, anxiety and somatoform domains of mental health had been more significantly correlated in women than men (P=0.006 , P=0.025) .Of quality of life domain, physical function is more significant in men than women (P=0.03) and bodily pain is more significant in women than men (P=0.001) .

Conclusion: According to the findings, many quality of life domains were correlated with mental health domains and cancer had effect on different aspects of patients' life.