This paper presents the externalities of sulfur dioxide (SO(2)) in the Taichung metropolitan, Taiwan. The human effects of SO(2) from stationary sources are a key element for local air quality management. A methodology to evaluate those effects in monetary term had been adapted and applied. This method was modified from the EU-based impact pathway approach link to the skill of geographic information systems. The studied area was divided into 66 districts and the quantity of SO(2) was allocated to each district. Then, the ambient concentration of SO(2) was estimated by using the ordinary kriging method. A risk analysis was employed to characterize the health impacts caused by SO(2). Finally, a monetary transfer approach based on the European data was conducted to estimate local damage costs per ton of SO(2). Health impacts, especially acute mortality, dominate in term of costs. The calculation showed that damage costs ranged from 0.56 to 7.38 USD/kg SO(2) based on the 2002 emission data. The results could be used in the internalization of SO(2) externalities and management of the stationary sources in the studied area. This paper also concludes that the externalities caused by stationary-related SO(2) emissions are some 28.5 million US dollars in Taichung metropolitan (Taiwan) in 2002.