Polycyclic aromatic hydrocarbons (PAHs) are one of the main components of urban air pollution. The level of concentration PAHs and effects are depended on seasonal variations and amount of exposure to PAHs. Nowadays, PAHs are one of the important pollutants that threat the public health. The purpose of this study was to evaluate the polycyclic aromatic hydrocarbons of the outdoor air in Ahvaz, southwest Iran using active sampling system during the warm and cold seasons of 2016. Data collection was performed daily during the study period in three stations in Ahvaz citizens at industrial, high traffic and residential areas. Omni sampler and equipped with PTFE filters (8*10) were utilized for sampling in this study. Gas chromatography with mass spectrometry (GC/MS) were utilized for detection of PAHs concentration (ngm(-3)). Statistical SPSS software (SPSS version 16) was used to determine the effects of PAHs during warm and cold season. According to result this study, the industrial and residential areas had the highest and the lowest PAHs concentrations. Based on result this study, PAHs concentrations in three main areas at industrial, high traffic and residential were 7.021 +/- 3.45, 5.162 +/- 2.63 and 4.187 +/- 1.76 ngm(-3), respectively. The results showed that the average concentration of polycyclic aromatic hydrocarbons in three main areas outdoor air in Ahvaz were more than recommended scales by international organizations. According to this study, the mean of PAHs concentration in different areas was significantly higher than standard. Results showed that the short-term exposure to PAHs during cold season were higher than the levels of exposure during warm season. The levels of exposure to PAHs can increased risk of health endpoint and the oxidative stress.