OBJECTIVES: Asthma is a prevalent condition world-wide, but little is known of the awareness and impact of the condition among Brazilian adults.  The current study assessed awareness of asthma and whether asthma is associated with decreased health-related quality of life (HRQoL) among Brazilians aged 18 years and older. METHODS: Data were taken from the 2011 Brazil National Health and Wellness Survey (n=12,000), a cross-sectional self-report survey which included the SF-12 Health Survey Version 2 (SF-12v2) to assess HRQoL.   Differences between patients with and without asthma were identified using chi-square tests for categorical variables and t-tests for continuous variables.   Multiple regression was used to assess the association of asthma with HRQoL while accounting for potential confounds, including age, gender, number of co-morbid conditions, possession of private insurance, alcohol use, exercise behavior, and cigarette smoking. RESULTS: Seventy-six percent (n=9108) of respondents were familiar with asthma.  Physician diagnosis of asthma was reported by 4% of the sample (n=415), and the remaining 96% (n=11,585) served as the control group.  Asthma patients were younger (36 vs. 41, p<0.001), more likely to be female (61% vs. 50%, p<.001), have private insurance (60% vs. 53% p<0.01), drink alcohol (68% vs. 60%, p<.01), and had more co-morbid conditions (0.73 vs. 0.32 p<0.001).  Relative to controls, asthma patients had lower MCS (42.41 vs. 46.99, p<0.001), PCS (47.27 vs. 50.58, p<0.001) and SF-6D health utilities (0.66 vs. 0.73, p<0.001).  Asthma was associated with significantly lower HRQoL after adjusting for age, gender, drinking, smoking, exercise, insurance, and comorbidities, with MCS lower by 2.59 points (p<0.001), PCS lower by 3.15 points (p<0.001), and SF-6D lower by 0.05 points (p<0.001).     CONCLUSIONS: Asthma is associated with significant HRQoL burden, even after adjusting for covariates.  This analysis may underestimate the burden of asthma, as undiagnosed asthma patients were likely included in the control group.