Data comprise radiocaesium concentrations in soil, vegetation, wildlife and fungi analysed from samples collected from throughout Great Britain after the 1986 Chernobyl accident by the Centre for Ecology & Hydrology (CEH), formerly the Institute of Terrestrial Ecology (ITE). National level vegetation surveys were conducted in May 1986, October 1986 and Spring 1987. More intensive surveys of vegetation (grass and heather) and wildlife (grouse, fox, etc.) in restricted areas were carried out in Cumbria, Wales and North Yorkshire in 1989, 1990, 1991 and 1993. Surveys of fungi were carried out between 1994 and 1997. The data are suitable for interpolation to create spatially variable surfaces suitable for input into models. Full details about this dataset can be found at https://doi.org/10.5285/d0a6a8bf-68f0-4935-8b43-4e597c3bf251