Ready Mixed Concrete (RMC) plants mix cement, sand, aggregates and water to produce a ready-to-use material. In the present study, pollutants emitted from RMC plants as particulate matter (TSP, PM10 and PM2.5), and gaseous pollutants (CO, NO2, SO2, H2S and VOC) were monitored at working areas from five RMC Plants in Cairo, Egypt, during 2019. The mean concentrations of TSP, PM10 and PM2.5 during different processes in RMC plants were 0.28-3.23 mg/m3, 0.11-1.45 mg/m3 and 0.07-0.64 mg/m3, respectively. The total emissions rate of TSP, PM10 and PM2.5 from RMC plants were 0.78-1.42 g/s, 0.24-0.43 g/s and 0.03-0.06 g/s, respectively. Higher emission rates of gases were recorded at plants with higher working hours, higher generator consumption of diesel and higher equipment consumption of diesel. Finally, result shows that the main sources of PM and gaseous pollutants in RMC plants are mixer process, truck movement on unpaved roads and using generators. Recommendation for RMC plant are: it should be cover storage areas; use water sprayer system for loading sand and aggregates; use control system at mixer area; and roads inside RMC plant should be paved and washed every day.