Abstract The emission of polycyclic aromatic hydrocarbons (PAHs) from various industrial stacks (blast furnace, basic oxygen furnace, coke oven, electric arc furnace, heavy oil plant, power plant and cement plant) in southern Taiwan were investigated. PAH concentrations ( μg/N m 3) and PAH emission factors ( μg/kg feedstock) were determined. In addition to these eight stationary industrial stacks, an industrial waste incinerator, a diesel engine and a gasoline-powered engine were selected and combined for the identification of source indicatory-PAHs in this study. The qualitative contribution of PAHs to the ambient air by various sources was estimated by factor analysis. Combustion of heavy oil produced considerably higher 4, 5 and 6+7-ring PAH concentration than other stacks. In addition, the HMW (higher molecular weight) PAH concentrations were significantly higher for the coke oven, the electric arc furnace and heavy oil combustion. Measured total-PAHs emission factors of eight stationary sources were between 77.0 and 3970 μg/kg feedstock, while BaP (the most carcinogenic PAH) emission factors were between 1.87 and 15.5 μg/kg feedstock. Among these eight emission sources, the heavy oil plant had both the highest total-PAH and the highest BaP emission factor. Indicatory PAHs of the cement plant were AcPy, Acp and Ant, which are all 3-ringed PAHs. However, the indicatory PAHs of the industrial waste incinerator were IND and CHR. For mobile sources (diesel- and gasoline-powered vehicles), the indicatory PAHs were mainly lower molecular weight PAHs (AcPy, FL and Flu). By using factor analysis, the cursorily qualitative analysis of PAH emission was found to be practicable.