<p>Over the last few decades, the evidence on the adverse effects on the health of air pollution has been raised. Mortality is the most important health effect of ambient air pollution. We studied the relation between mortality and criteria pollutant air in Tehran, one of the highly industrialized, densely populated area and most polluted cities of the reign, during 2005-2014. For this purpose, we applied the approach proposed by the World Health Organization using the AirQ 2.2.3 model. Hourly concentrations of pollutants were taken from the Tehran environmental protection agency and Air Quality Control Company. In this model, the attributable proportion of health outcome, the annual number of excess cases of mortality for all causes were estimated. According to results, the number of total mortality caused by exposure to O3, NO2, SO2, PM10, PM2.5 in the past decade was 8042, 15141, 8136, 17776 and 20015 cases, respectively. The number of cumulative total mortality was 53110 cases in ten years. Furthermore, the number of cumulative cardiovascular and respiratory mortality 33887 and 8168 cases was estimated in last decade. A large number of residents of Tehran have died as a result of exposure to air pollutants; therefore for control and management of air pollution, appropriate actions on health and the environment should be performed.</p>