Halogenated polycyclic aromatic hydrocarbons (Halo-PAHs) are a new group of PAH derivatives of which some were reported to show adverse impacts on human health than their corresponding parent PAHs. In this study, passive air samplers equipped with polyurethane foam (PUF) disks were used to monitor the pollution of Halo-PAHs at 20 sampling sites in Ulsan during four seasons in 2013 to investigate the seasonal variation. Among the target 21 chlorinated PAHs (ClPAHs) and 9 brominated PAHs (BrPAHs), 9-ClPhe and 2-BrFlu were the most abundant species in the atmosphere with the annual mean concentrations of 49-123 pg/m3 and 0-482 pg/m3, respectively. Halo-PAHs were recorded to be higher in warm seasons than in cold ones and were greatly influenced by the wind patterns in Ulsan. This is so far the first study reporting atmospheric levels of Halo-PAHs in South Korea and necessary to investigate further for deeper understanding about their behavior in ambient air.