Medellin and surrounding municipalities make up a metropolitan area with high population density, with a lot of industrial, business, social and service activities. Everything is concentrated in a narrow valley with low levels of ventilation. All these industrial and transportation activities deposit into the air large amounts of pollutants that local community have forcefully to breath. To analyze air quality in Medellin and surrounding metropolitan area. Air pollutants are explored for the last several years in Medellin and its Metropolitan Area based on monitoring data crossed with additional measurements campaigns to ensure quality in the information being analyzed. Total suspended particles (PST) and breathing particles (PM10) are found in levels above 200-400% of precautionary limits as defined by the World Health Organization (WHO). The tendency is going from bad to worse along with the increase in density of people, buildings and motor vehicles. There are also other pollutant gases with some concern for Nitrogen Oxide and Ozone; the concentrations of the other gases are at low levels. Air pollution in the metropolitan area of Medellin is high, dealing with breathing particulate matter and must be causing undesirable effects on the health of the local inhabitants.