This paper presents an Air Quality Monitoring System for the city of Cartagena de Indias.The goal of this system is to monitor the air quality in the city and to establish the current state of the air Cartagena's citizen breathe.Data is going to be acquired through a sensor network, and the information is going to be displayed on web or mobile application allowing access from anywhere in the world to anyone that may be interested.It is expected that the availability of this information allows research centers, educational institutions, and government to design plans for prevention and improvement of the air quality in the city based on historical and real-time data. I. INTRODUCTIONAccording to the 2017 Cartagena's Quality of Life Report from "Cartagena Como Vamos" [1], it is not possible to establish the state of the environment in Cartagena, because there are no up-to-date measurements on both air and noise, which not only ratifies what was previously affirmed, but also the need for information to serve as a key instrument for making quick and timely decisions, as well as a key tool for the achievement of new projects for a city in constant growth.Based on the Air Quality Diagnosis of Cartagena de Indias in 2014 and 2015, air quality in Cartagena was moderate at that time.For 2014 available information is insufficient in terms of concentration of pollutants.From the 11 monitoring equipments operating that year, just six of them had information availability equal to or greater than 75% of the annual data.Meanwhile, during 2015 the number of stations operating integrated to the Air Quality Monitoring System increased from four to five but none provided an amount equal to or greater than 75% of the total annual data.For those years, Cartagena's Air Quality Index for O3 indicated good air quality, for PM10 it is mostly a good air quality with isolated events where a moderated air quality was presented, and for PM2.5 a moderate air quality is reported and sometimes unhealthy for sensitive groups [2].A 2016 report, Design of the Intelligent System of Environmental Quality Monitoring of Cartagena District, estimated that the Air Quality Index for the locations Bomba del Amparo, Peaje de Ceballos, and Maria Auxiliadora was, in all three cases, between Unhealthy for sensitive groups and Unhealthy.The highest concentrations of pollutants is located in high vehicular traffic sectors, such as Peaje Ceballos and Bomba del Amparo [3].