Background: The purpose of the study was to investigate and compare the family function and quality of life in patients with schizophrenia and bipolar spectrum disorders. Methods: A sample included 52 patients with schizophrenia and 58 patients with bipolar spectrum disorders that referred to Sahamie hospital were selected through convenience sampling method. They were asked to answer the family assessment device and quality of life questionnaire. Data were analyzed by independent t-test statistics in SPSS. Results: Results showed that the two groups have no significant difference in family function and quality of life. Patients with schizophrenia spectrum disorders obtained the lowest score in the behavioral control and roles subscales of FAD and patients with bipolar spectrum disorders obtained the lowest score in the behavioral control and problem solving of it. Additionally, patients with schizophrenia spectrum obtained the lowest score in the physical and social relations dimensions of quality of life inventory. The ones with bipolar spectrum obtained the lowest score in the social relations, physical, and psychological dimensions of it. Conclusions: These findings confirm the results of previous studies that showed patients with schizophrenia and bipolar spectrum disorder had family dysfunction and bad quality of life. It is important to pay attention to these factors during assessment, measurement, and implementation of treatment strategies.