We investigated the air quality changes from 2003-2013 in Istanbul, Turkey. We studied SO , CO and PM concentration patterns in 10 districts of Istanbul. The data was obtained from air pollution monitoring stations of Istanbul Metropolitan Municipality Environmental Protection Department. We compared the variations of mean concentrations monthly, yearly and seasonally. The winter season was accepted from Oct to Mar and the summer season from Apr to Sep. The highest monthly average values for all measurements of sulfur dioxide and CO were 12.61, 949.19 μg/m in Sarachane respectively. The Highest value of the monthly average of the Particulate Matter was 72.07 μg/m in Kartal district. During the period between 2003-2013, monthly mean concentration values of different districts differed significantly in levels of SO ( =0.012), CO ( =0.029), and PM ( =0.024). The emissions of air pollutants (SO , PM, and CO) decreased considerably from 2003 to 2013.