The objectives of this study were to determine the environmental impacts of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/Fs) emitted from two typical municipal solid-waste incinerators (MSWIs), named M and L, in China. The main differences between the two MSWIs relate to incineration technologies, treatment capacities, emission standards and meteorological conditions. The distribution of PCDD/Fs in the surrounding ambient air and soils of the MWSIs were monitored and compared. In addition, air dispersion models and health risk assessments were combined to determine the behaviour and transport of PCDD/Fs. The results indicated that higher PCDD/F emission levels resulted in higher concentrations in the surrounding environment. The average PCDD/F levels emitted from the M MSWI was about seven times higher than those emitted from the L MSWI and about 10 times and 2 times higher in air and soils, respectively. The simulation results were similar to the trend of the monitored results. Both the observed and the simulation results suggested that the atmospheric pollution by PCDD/F surrounding the M MSWI was relatively serious; the environmental impact of the L MSWI was not significant.