This study addresses the question: Is the disproportionate burden of asthma or asthma-like symptoms among low socioeconomic status individuals related to greater pollutant exposures, greater vulnerabilities, or both? Using Geographic Information System (GIS) software, we linked California Health Interview Survey (CHIS) 2003 respondents’ residential addresses to government air monitoring stations for O₃, PM10, PM2.5, and NO₂. We calculated annual pollutant averages and days exceeding air quality standards and assessed traffic density and residential distance to roadways. Higher exposures were estimated for low income and racial/ethnic minority respondents with asthma for NO₂, PM10, and PM2.5, but not O₃. Among adults with asthma, we observed increases in adverse asthma outcomes, such as daily/weekly symptoms, asthma attacks, daily medication use, and asthma-related work absences and emergency department visits with increasing annual average pollutant concentrations. Among children with asthma, daily asthma medication use and school absences were associated with increased annual average NO₂ concentration. Similar positive associations were observed between O₃, PM10, and PM2.5 exceedance days and asthma outcomes, mainly for adults. When adjusting for confounders, associations between pollutants and asthma outcomes persisted. Notably, racial/ethnic minority and low income respondents had greater increases in adverse asthma outcomes for similar increases in NO₂ and PM10 exposures.