This dataset consists of behaviour and distribution data of Lepidoptera from chalk grassland fragments at the Stonehenge World Heritage Site in Wiltshire, UK, in 2011. The landscape consists of small fragments of ancient chalk grassland on slopes and groups of burial mounds (barrows) which have retained many of the characteristic chalk grassland plant and butterfly species. Surveys were located at four of these chalk grassland fragments. At each chalk grassland fragment, four 20 m long survey boundaries, were set up on boundaries with adjacent land cover of either arable land or new grassland re-creation sown in the years 2009 or 2010. Control surveys were also carried out in areas of continuous habitat within the chalk grassland fragment and in the adjoining land cover type. Surveys of Lepidoptera behaviour were carried out from May to July between 10am and 4pm and effort was taken to survey the same site at different times of the day in order to minimise the effect of survey time on behaviour. Standing at the chalk grassland fragment edge the flight path of individual Lepidoptera was tracked in the survey area for up to three minutes. Measures of vegetation characteristics and nectar flower availability were recorded for each plot. Vegetation characteristics were measured as vegetation height and density and the percentage cover of bare ground and dead vegetation. Nectar resources were measured in terms of the number and percentage coverage of flowering units, the total number of nectar flowering units and of relevant families (Dipsacaceae, Fabaceae and Asteraceae). The data were collected as part of a PhD project funded by the Natural Environment Research Council and the National Trust. Full details about this dataset can be found at https://doi.org/10.5285/61561232-3307-470a-b8dc-a923b25e1641