The Natural History Museum Rotterdam (NMR) is a regional natural history museum in The Netherlands that focuses on nature and biodiversity of the city of Rotterdam and its surroundings. Bureau Stadsnatuur Rotterdam (bSR) is part of the NMR and collects, mainly on behalf of third parties, data on the flora and fauna from primarily urban areas. The NMR has received a large amount of observation data (1,363 different species in 886,902 observations), in particular of moths and mainly from the Provinces of Zuid-Holland, Noord-Holland and Noord-Brabant from the period 1947-2020. The observation dataset was compiled and standardised from 18 different datasets and stored in a database and published at the Global Biodiversity Information Facility (GBIF). For the first time, a large butterfly and moth observations dataset with historical distribution data for The Netherlands is mobilised and serves as a baseline lepidopteran biodiversity record.