Dioxins and furans are persistent, toxic compounds that are inadvertently introduced into the environment through the combustion of organic materials containing trace amounts of chlorine. This report, No. 10 in the UKSHS report series, presents data on 17 polychlorinated dibenzo-pdioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in soil and herbage collected from 203 rural, urban and industrial sites in England, Northern Ireland, Scotland and Wales. The results are discussed in terms of median concentrations as all the data are strongly skewed. Because of the persistence of dioxins, the results for dioxin concentrations in soils reflect emissions and depositions over the last 10–30 years. The results indicate that, historically, land use was the main determinant of dioxin concentrations. Median concentrations in urban and industrial soils are approximately 2–3 times those in rural soils, almost certainly reflecting the presence of significant localised dioxin sources in urban and industrial areas during the previous 10–30 years. The exception is Northern Ireland, where dioxin concentrations in rural and urban soils are similar.