In this study, temporal and spatial variations of the atmospheric concentrations of polychlorinated-p-dibenzo dioxin (PCDDs) and polychlorinated dibenzofuran (PCDFs) congeners were investigated in Istanbul at three different locations. The highest average concentration (3481 fg/m(3)) was observed at the sampling location which is characterized by mixed source groups during colder months. The lowest average concentration (749 fg/m(3)) was observed at sampling station which is characterized by semi-urban characteristics. Sigma PCDD/F concentration showed seasonal variation in this study. The highest average concentration was determined to be 4373 fg/m(3) in winter while the lowest average concentration was determined to be 498 fg/m(3) in summer. (C) 2013 Elsevier B.V. All rights reserved.