OBJECTIVES: Pharmacoeconomic models in diabetes link blood glucose control as measured by hemoglobin A1c to diabetes-related complications.  Despite advances in diabetes modeling, there is limited research on the relationship between A1c and health-related quality of life (HRQoL) that is independent of diabetes-related complications.  Our objective was to quantify the cross-sectional relationship between A1c and HRQoL utility scores in adult type-1 diabetes (T1D) patients, after adjusting for diabetes-related complications. METHODS: The EuroQoL-5 dimensions (EQ-5D) questionnaire was administered to adult T1D patients during one clinic visit at the University of Colorado Barbara Davis Center for Diabetes (BDC) from November 2011 – July 2012.  We combined individual-level data from the EQ-5D questionnaire with A1c data from the BDC medical record. Utility scores were derived using the US time-tradeoff valuation of the EQ-5D.  Unadjusted mean utility scores were estimated for the overall population and stratified by A1c.  We used ordinary least squares regression with robust standard errors to estimate the cross-sectional relationship between A1c and utility, adjusting for demographic variables and diabetes-related complications. RESULTS: Mean (SD) age in years for the population (N = 176) was 38 (12.2); duration of diabetes in years was 22 (12.1); and number of chronic conditions other than diabetes was 2.7 (2.0).  Unadjusted mean (SD) utility was 0.94 (0.09) for those with A1c levels < 7% (n = 54); 0.89 (0.15) for those with A1c ≥ 7% (n = 122); and 0.91 (0.14) for all patients.  On average, a 1% absolute increase in A1c was associated with a significant disutility of -0.03 (95% CI: -0.06, -0.006), after adjustment. CONCLUSIONS: Findings suggest that after adjusting for diabetes-related complications, poor blood glucose control is associated with decrements in utility not currently captured in existing diabetes pharmacoeconomic models.  Longitudinal research is needed to strengthen this cross-sectional evidence on the relationship between A1c and HRQoL utility.