Soil samples collected from Rothamsted Experimental Station in southeast England at various times since the mid-1800s and up to the present have been analyzed recently for polynuclear aromatic hydrocarbons (PAHs). All the soils were collected from the plough layer (0–23 cm) of an experimental plot for which atmospheric deposition will have been the only source of PAH input. The total PAH burden of the plough layer has increased approximately 4-fold since the 1880/ 1890s, with some compounds (notably, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[e]pyrene, pyrene, benzo[a]-anthracene, and indeno[1,2,3-cd]pyrene) showing substantially greater increases. Average rates of increase for individual PAHs in the Rothamsted plots over the century since 1880/1890 are similar to contemporary atmospheric deposition rates to semirural locations. Regional fallout of anthropogenically generated PAHs derived from the combustion of fossil fuels will be the principal source of PAHs to the Rothamsted soils. It is suggested that the increases in soil PAHs observed this century at Rothamsted are representative of those likely for agricultural soils in many industrialized countries or regions.