The aim of the study was to investigate the effects of liquid inhibitor (known as De-dioTM) on the emission of dioxin-furan from medical waste incineration plants. Various concentrations of De-dioTM solutions were tested on the medical waste incinerator combustion chamber with an injection flow rate of 1.5 L/min. The sampling protocol of US EPA Method 23 was adopted to collect the sample using a modified US EPA Method 5 sampling train. The flue gas emission was collected before and during the injection of the chemical. The result showed that the De-dioTM was able to reduce or minimize the formation of dioxin-furan to meet its regulatory limits. The study illustrates that the higher the concentration of De-dioTM solution, the lower the dioxin-furan emission was observed in the flue gas.