In many previous studies, indoor-mold contamination is associated with an increased risk of asthma and respiratory illness. This study sampled indoor-mold contamination and measured the prevalence of asthma/respiratory illness in two low-income, Latin@ communities, Mecca and Coachella, in the Eastern Coachella Valley (ECV) of California. The study consisted of a random household health survey that included questions designed to assess asthma/respiratory illness coupled with an environmental assessment that measured mold contamination in house-dust samples using the Environmental Relative Moldiness Index (ERMI) scale. Our data show about 11% of adults and 17% of children in both Mecca and Coachella suffer from asthma/respiratory illness. The average ERMI values in Mecca and Coachella housing (10.3 and 6.0, respectively) are in the top 25% of ERMI values for United States (US) homes. Overall, the homes surveyed in these California communities had an average prevalence of occupant asthma of 12.8% and an average ERMI value of 9.0. The prevalence of asthma/respiratory illness in the Latin@ communities of Mecca and Coachella and the mold contamination in their homes appear to be greater than the averages for the rest of the US. The higher levels of mold contamination in their homes appears to be associated with a greater risk of asthma/respiratory illness for these low-income, Latin@ communities.