Total suspended particulate (TSP) matter and smoke were investigated at Shoubra El-Kheima industrial area and El-Dokki residential area located in Cairo. TSP gave the highest monthly mean concentration in 2 years' study at Shoubra El-Kheima (895 μg m −3), nearly 12 times the geometrical mean of air quality standard (75 μg m −3). The corresponding figure at the residential area is 544 μg m −3, which is 7.3 concentrations during spring and lower during summer. Smoke concentration in the industrial area was nearly 1.4 and 1.2 times its concentration in the residential area during the 2 study years. Smoke concentration was found to be light to moderate during 86% of the days and heavy to extremely heavy during 14% of the days at the industrial area. The corresponding percentages for the residential area were 90% and 10% for light to moderate and heavy to extremely heavy, respectively.