For unintentionally generated persistent organic pollutants such as polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), the development and maintenance of national release inventories is an obligation for parties to the Stockholm Convention on Persistent Organic Pollutants. About 20 years after the first dioxin inventories have been published, a systematic approach has been developed and now is applied worldwide to establish complete, comparable inventories that are consistent in format and content. The basis for such inventories is the “Toolkit,” a collection of emission factors and description of activities and processes that form and release PCDD/PCDF. The Toolkit uses a five-vector approach, i.e., not only releases to air but also to other compartments such as water, land, product, and residue are included. The assessment of the quantitative data for releases from ten source groups to five release vectors provides interesting insight in the country’s geographic, economic, and development status. After the first round of reporting PCDD/PCDF inventories, 86 inventories have been assessed, and it can be seen that the total releases of PCDD/PCDF from the ten source categories have a positive correlation with the size of the population and a negative correlation with economic status.