A set of 45 samples of sludge from wastewater plants in the Czech Republic were collected. The selection of a wastewater plant reflected the extent of the observed area (district towns and smaller settlements) as well as the occurrence of industrial wastewater. The background values of selected persistent organic pollutants (POPs) from the group of polyaromatic hydrocarbons (PAHs), PCB6, DDT and DDT residues were processed in the set of samples. The contents of polychlorinated dibenzo[1,4]dioxines and dibenzofurans (PCDD/F) were measured in 16 sludge samples. Two selected sludge samples with maximum load of POPs were used for pot and field test where the fate of POPs and their transfer into plants were observed. The maximum values of selected POPs in the sludges for agricultural soil applications were recommended on the basis of own results and a proposed EU directive draft.