Particulate matter 2.5 micrometer (PM2.5) emission increased with increasing number of urban population as a result of increasing number of motor vehicles for their daily transportation. This study aimed to determine the level of impaired lung function and asthma and its relation to ambient levels of PM2.5 among migrant communities in Tangerang and Makassar and socioeconomic conditions. A cross-sectional design was implemented by involving 4,250 and 2,900 respondents in Tangerang and Makassar respectively on April to September 2010. Cluster sampling approach was applied. PM2.5 ambient measurements in each city were based on the coordinates of 40 global positioning system locations. The PM2.5 levels found higher in the morning than afternoon in both cities, with average about six folds of WHO guideline of 35 mg/m3. Asthma prevalence was found similar in both cities (1.3%) and impaired lung function prevalence in Makassar was higher (24%) than Tangerang (21%). Data showed there was no association between PM2.5 levels to the prevalence of asthma and impaired lung function in both cities. The study confirmed that exposure to PM2.5 is associated with prevalence of asthma and impaired lung function and provided evidence showed that the effect of air pollution was modified by certain living environment characteristics. These findings suggest the improvement of housing ventilations and larger space of living room for better oxygen circulation.