Polycyclic Aromatic Hydrocarbons (PAHs) are toxic pollutants released by various urban combustion sources. Tehran is the largest city in Iran with a population of about 8 million and it is faced with serious air quality problems. The gas phase samples collected from 21 sites in Tehran area throughout year 2005. The samples‘ PAHs were collected using a SKC trapping consisting of glass cartridge packed with XAD-2 resin supported by two polyurethane foam plugs. Sixteen PAHs were analyzed by HPLC with two detectors (fluorescence; UV-Vis) according to U. S. Environmental Protection Agency methods.The average concentrations of PAHs ranged from 16068.98 μg/m3 for Bahman site to 1000.24 μg/m3 for Nour site. The species that presented higher concentration were Acenaphtylene (2674.74 μg/m3), Naphthalene (2467.71 μg/m3) and Acenaphtene (1245.22 μg/m3). The PAHs with two and three rings were responsible by 87 % of the total concentration among 16 PAHs. A major source of PAHs, in Tehran area is related to traffic and the number of gasoline and diesel vehicles.