The impact of the increased sulfur dioxide emissions within the Greater Cairo Urban Region over the part 50 yr has been overwhelming. While previous air-pollution surveys measuring SO2 levels in the region converged upon the study of emissions from specific industrial activities, no correlation between the measured concentrations and the induced health-related impacts in living environments was provided. As well, no inventory of emissions from other sources within some residential areas were accounted for or evaluated. During the study period of January to April 2000, the ambient sulfur dioxide levels in four residential locations within the capital region were investigated. The results indicated that the measured cumulative ambient SO2 concentrations were in excess of the national and the international monthly mean exposure limits, irrespective of the type of local activity. As well, measurements within three of the selected environments surpassed the 0.5 ppm SO2 odor-threshold. The data also showed a significant dependency of the measured content upon the physical layout and topography of the studied environment as well as with respect to the prevailing seasonal weather conditions.