Our results showed that both socioeconomic and chronic complications are relevant factors of HRQOL in type 1 and 2 diabetes mellitus patients. Age, rural lifestyle, retirement, lower level of education and low socioeconomic status, as well as DM complications (angina pectoris, hearth failure, diabetes nephropathy, and diabetes retinopathy) were found to be independent risk factors for the component scores of SF-36 and EQ-VAS score. Taking into consideration the results obtained, health practitioners should be aware not only of the clinical parameters of patients with DM, but also of their educational level and working status.