Incineration of plastic refuse in existing facilities is often said to increase the emissions of harmful gases such as dioxins. In the present study, the change in emissions when plastic refuse mixed with normal burnable refuse was incinerated was investigated using the facilities in Musashino City. In the operation of incinerators, it is necessary firstly to control the generation of dioxins and their precursors in the burning process, and secondly to achieve highly then the highly effective removal in the gas treatment facilities. The dioxin concentration at the boiler exit or the stack did not show any relationship with plastic content in the mixed refuse for incineration. The dioxin concentrations at the boiler exit ranged 1.2-2.3 ng-TEQ/m(3)N, while those at the bagfilter exit were drastically reduced to around 1% of those at the boiler exit. Those at the stack ranged 0.12-0.33 ng-TEQ/m(3)N, being well below the regulation standard value effective since Dec. 2002 of 5 ng-TEQ/m(3)N for am incinerator with capacity of 2-4 t/h. In conclusion, incineration of burnable refuse mixed with plastic refuse does not result in a drastic increase in dioxin concentration at the stack. No effects on various other emissions, such as NOx, CO, and HCl, were found, though the treatment cost of HCl may be increased, and the local temperature in the furnace still needs to be measured. Based on these test results, Musashino City decided to collect the plastic as burnable refuse for incineration from October, 2003.