Mental health and health related quality of life is commonly affected in patients with chronic problems and their caregivers. In the present study, it was aimed to assess depression and anxiety in patients with beta thalassemia major (BTM) and in their caregivers; and to evaluate effects of these disorders on quality of life. The study was carried out in a district Hereditary Hemoglobinopathy Center and included 88 patients with BTM and 63 of their caregivers. All subjects were assessed using Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and Short Form-36 (SF-36) by a trained psychiatry resident via face-to-face interview. The BDI scores were 17 or above in 20.5% of the patients with BTM and 28.6% of their caregivers (P = 0.248). Of the patients with BTM, there were mild anxiety symptoms in 19.3%, while moderate and severe anxiety symptoms in 14.8% and 4.5%, respectively. Anxiety levels were similar between the patients with BTM and their caregivers (P = 0.878). It was found that BDI and BAI scores were negatively correlated to scores of physical health and mental health components of SF-36 in patients with BTM and their caregivers. In linear regression analysis, it was seen that depression affected physical and mental health of the patients with BTM and their caregivers regardless from anxiety. BTM leads an increase in the frequency of depression and anxiety in both patients and their caregivers, and affects negatively physical and mental components of quality of life.