Grainsize data supports palaeoclimatic reconstruction of glacial/interglacial cycles for the Middle Pleistocene sediment record from the crater basin of Rodderberg, Germany. A sediment record measuring 72.8 m in length was retrieved by employing wire-line drilling techniques, utilising 3 m-long liners, from the silted-up crater basin of Rodderberg (East Eifel Volcanic Field) in the vicinity of the city of Bonn, Germany. For the purpose of grainsize analysis, the composite record ROD11 was systematically subsampled at a spatial resolution of 2 cm and examined through a laser diffraction particle size analyser (Beckman Coulter LS 13320). The resulting sedimentological data characterise glacials as silt-dominated (aeolian sediments: loess), interglacials as sand-dominated (runoff-related deposits from the step crater walls) and clay dominance for the Holocene soil. The terrestrial sediment record has been evaluated through multiple dating techniques and it provides a comprehensive environmental reconstruction since the Middle Pleistocene, thus providing valuable insights into the region's climate history.