Background: Treatment of patients with type 2 diabetes mellitus (T2DM) continues to present challenges. Despite available treatments, therapeutic efficacy is offset by side effects such as weight gain, hypoglycemia, fluid retention, and GI symptoms. Health-related quality of life (HRQOL) has been found to be lower among adults with T2DM than in those without T2DM. Dapagliflozin is a novel, oral, highly selective, sodium-glucose co-transporter 2 (SGLT2) inhibitor that reduces hyperglycemia independent of insulin secretion or action in T2DM patients by increasing urinary glucose excretion. This mechanism of action, while providing benefits of HbA1c reduction, weight loss, and blood pressure lowering, may also lead to increases in urine volume and risk of genital infection. Thus, it is important to understand the impact of dapagliflozin treatment on T2DM patients’ HRQOL. Objective: Our aim was to evaluate HRQOL and health state in T2DM patients with high CV risk in a clinical study with dapagliflozin vs placebo using EuroQoL Group EQ-5D, a standardized measure of health status designed for self-completion by respondents and composed of a descriptive system (index) and visual analogue scale (VAS). Methods: Patients were enrolled in a 24-wk, international, randomized, double-blind, age-stratified, placebo-controlled phase 3 study with a 28-wk extension period to evaluate the efficacy and safety of dapagliflozin 10 mg once daily ( NCT01031680 ), including data from 914 patients (men 68.3%; mean age, 62.9 yrs) with T2DM, CV disease, and hypertension with inadequate glycemic control on usual care (HbA1c ≥7.0% and ≤10.0%). Patients treated with dapagliflozin 10 mg were compared with patients given placebo based on a mixed model with treatment group, age stratum, and rescue as categorical factors and baseline EQ-5D values, treatment week, interaction of treatment group by week, and interaction of baseline by week as continuous covariates. Results: EQ-5D index baseline means (SD) were 0.78 (0.20) and 0.79 (0.19) for dapagliflozin and placebo, respectively. Corresponding 52-wk values were 0.81 (0.19) and 0.79 (0.20), respectively. There was an improvement in EQ-5D index score from baseline to wk 52 for patients treated with dapagliflozin; however, this was not statistically significant vs placebo (0.01; CI [-0.01, 0.04]; p=0.2766). EQ-5D VAS baseline means (SD) were 67.3 (24.45) and 68.1 (23.08) for dapagliflozin and placebo, respectively. Corresponding 52-wk values were 75.3 (20.80) and 73.5 (19.96), respectively. EQ-5D VAS improved in both groups from baseline to wk 52; however, there was no significant difference between groups in the mean change from baseline at wk 52 (0.6; CI [-2.1, 3.2]; p=0.6839). Conclusion: The results of this study indicate that HRQOL is maintained at a high level over a 52-wk period in T2DM patients with high CV risk treated with dapagliflozin, a novel SGLT2 inhibitor.