Dioxin is formed as an unintentional by-product of many industrial processes involving chlorine, such as waste incineration, chemical and pesticide applications, pulp and paper bleaching, and sintering plants. At the moment, the iron sintering process is the principal PCDD/F source. Iron sintering plants are associated with the manufacture of iron and steel, often in integrated steel mills. The sintering process is a pre-treatment step in the production of iron, where fine particles of iron ores are agglomerated by combustion. Agglomeration of the fines is necessary to enable the passage of hot gases during the subsequent blast furnace operation. In a sintering plant, many factors condition the PCDD/F formation; the sintering process can be unstable, and the operative variables are hard to check. Many authors suggest carrying out continuous monitoring to minimize the variables due to the process fluctuations. Therefore, we carried out 10 days monitoring, split in three campaigns of three samplings each.