Health-related quality of life (HRQoL) is a multidimensional concept that provides insight regarding the impact of a disease from the patient’s perspective and yield an important health outcome to evaluate treatment interventions and quality of health care. OBJECTIVES: The goal of this study is to reveal HRQoL of type 2 diabetes mellitus (T2DM) patients treated in the Brazilian private health care system. METHODS: A generic instrument to assess health status (EuroQol - EQ-5D), commonly used in diabetic patients worldwide, was applied in 383 outpatients with T2DM from 5 cities (Fortaleza, Porto Alegre, Rio de Janeiro, Ribeirão Preto e São Paulo). Euroqol uses five dimensions to describe HRQoL states (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) and a visual analogue scale (VAS) recorded by the patient and was measured during only one time during the visit to the physician. RESULTS: The group was composed of 201 women and 182 men, aged 60.5±9.6 years, mean BMI 29.1 kg/m2 and mean duration of diabetes of 12.2±8.75 years. For the entire group, mean EQ VAS score was 75.15±16.72, 24.5% reported some problems with mobility, 4.2% with self-care, 17.5% problems in their usual activities, 44.9% any pain/discomfort and 45.2% anxiety/depression. Mean EQ VAS score decreased as diabetes duration increased (78.19<9 years vs. 73.26>19 years of disease; p = 0.05). The patients without micro and macrovascular complications (41.5%) had a higher VAS compared to those with these complications (18%) (VAS 77.5 vs. 70.19; p=0.002). Retinopathy (VAS=68.13) and heart failure (VAS=67.05) were conditions associated with lower EQ VAS scores. Regarding the type of treatment, VAS was lower in insulin-treated patients compared to oral agents users (VAS=76.59 vs. 71.54; p=0,00004). CONCLUSIONS: A longer duration of diabetes, the presence of chronic complications and the use of insulin showed a negative impact on T2DM patient’s HRQoL.